Summary of significant accounting policies (Policies)	12 Months Ended
Dec. 31, 2011
Summary of significant accounting policies
Consolidation	The accompanying consolidated financial statements include the accounts and operations of the Company. All intercompany accounts and transactions have been eliminated. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Use of Estimates	The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates and assumptions.
Reclassifications	Certain reclassifications have been made to prior year amounts to conform to the current period presentation.
Subsequent Events	The Company considers events or transactions that occur after the balance sheet date, but before the financial statements are issued, to provide additional evidence relative to certain estimates or to identify matters that require additional disclosures.
Cash and cash equivalents	Cash and Cash Equivalents We consider all money market funds and highly liquid investments with maturities of three months or less at the time of purchase to be “Cash and cash equivalents”.
Investment securities	Investment Securities Investments designated as available-for-sale securities are carried at fair value, which is based on quoted market prices for such securities, if available, or is estimated on the basis of quoted market prices of financial instruments with similar characteristics. Unrealized gains and losses of the Company’s available-for-sale securities are excluded from earnings and reported as a component of “Other comprehensive income (loss)”. Investments with original maturities greater than 90 days and remaining maturities of less than one year are normally classified as “Short-term investments”. In addition, investments with maturities beyond one year may be classified as “Short-term investments” if they are highly liquid in nature and represent the investment of cash that is available for current operations. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in investment and other income, net in the consolidated statements of operations. The Company’s investments include auction rate securities (“ARS”). These ARS are variable rate bonds tied to short-term interest rates with long-term maturities. ARS have interest rates which reset through a modified Dutch auction at predetermined short-term intervals, typically every 7, 28, or 35 days. Interest on ARS is generally paid at the end of each auction process and is based upon the interest rate determined for the prior auction. The majority of our ARS are highly rated, and are typically collateralized by student loans guaranteed by the U.S. government under the Federal Family Education Loan Program or backed by monoline bond insurance companies.
Restricted cash - compensating balances	Restricted Cash—Compensating Balances Restricted cash is included within “Short-term investments” on the consolidated balance sheets. The majority of our restricted cash relates to a standby letter of credit required by one of our inventory manufacturers to qualify for certain payment terms on our inventory purchases. Under the terms of this arrangement, we are required to maintain with the issuing bank a compensating balance, restricted as to use, of not less than the sum of the available amount of the letter of credit plus the aggregate amount of any drawings under the letter of credit that have been honored thereunder, but have not yet been reimbursed.
Financial instruments	Financial Instruments The carrying amount of “Cash and cash equivalents”, “Accounts receivable”, “Accounts payable”, and “Accrued expenses” substantively approximate fair value due to the short-term nature of these accounts. Our U.S. treasuries, government agency securities, and mortgage-backed securities are carried at fair value, which is based on quoted market prices for such securities, if available, or is estimated on the basis of quoted market prices of financial instruments with similar characteristics. ARS are carried at fair value, which is estimated using an income-approach model (specifically, a discounted cash-flow analysis). Derivative instruments, primarily foreign exchange contracts, are reported at fair value in “Other assets” or “Other liabilities” in the consolidated balance sheet. The fair value of foreign currency contracts are estimated based on the prevailing exchange rates of the various hedged currencies as of the end of the period. Activision Blizzard transacts business in various foreign currencies and has significant international sales and expenses denominated in foreign currencies, subjecting us to foreign currency risk. We utilize foreign exchange forward contracts and swaps, with maturities of generally less than one year, to mitigate foreign currency exchange rate risk associated with foreign currency-denominated assets and liabilities. Activision Blizzard does not use derivatives for speculative or trading purposes, and the Company does not designate these derivatives as hedging instruments under ASC Topic 815. Accordingly, gains and losses resulting from changes in the fair values through the period are reported as General and administrative expenses or Investment and other income, net in the consolidated statements of operations, depending on the nature of the derivative.
Other-Than-Temporary Impairments	Other-Than-Temporary Impairments The Company regularly reviews its investments to determine whether a decline in fair value below the cost basis is other than a temporary impairment. If the decline is determined to be other-than-temporary, the cost basis of the investment is written down to fair value. For available-for-sale fixed maturity instruments where credit-related impairments exist, other-than-temporary impairments are reported in the consolidated statement of operations and non-credit impairments are reported in accumulated other comprehensive income (loss).
Software Development Costs and Intellectual Property Licenses	Software Development Costs and Intellectual Property Licenses Software development costs include payments made to independent software developers under development agreements, as well as direct costs incurred for internally developed products. We account for software development costs in accordance with the Financial Accounting Standards Board (“FASB”) guidance for the costs of computer software to be sold, leased, or otherwise marketed within ASC Subtopic 985-20. Software development costs are capitalized once technological feasibility of a product is established and such costs are determined to be recoverable. Technological feasibility of a product encompasses both technical design documentation and game design documentation, or the completed and tested product design and working model. Significant management judgments and estimates are utilized in the assessment of when technological feasibility is established. For products where proven technology exists, this may occur early in the development cycle. Technological feasibility is evaluated on a product-by-product basis. Prior to a product's release, we expense, as part of “Cost of sales—software royalties and amortization”, capitalized costs if and when we believe such amounts are not recoverable. Capitalized costs for those products that are cancelled or expected to be abandoned are charged to “Product development expense” in the period of cancellation. Amounts related to software development which are not capitalized are charged immediately to “Product development expense.” Commencing upon product release, capitalized software development costs are amortized to “Cost of sales—software royalties and amortization” based on the ratio of current revenues to total projected revenues for the specific product, generally resulting in an amortization period of six months or less. Intellectual property license costs represent license fees paid to intellectual property rights holders for use of their trademarks, copyrights, software, technology, music or other intellectual property or proprietary rights in the development of our products. Depending upon the agreement with the rights holder, we may obtain the right to use the intellectual property in multiple products over a number of years, or alternatively, for a single product. Prior to the related product's release, we expense, as part of “cost of sales—intellectual property licenses,” capitalized intellectual property costs when we believe such amounts are not recoverable. Capitalized intellectual property costs for those products that are cancelled or expected to be abandoned are charged to product development expense in the period of cancellation. Commencing upon the related product's release, capitalized intellectual property license costs are amortized to “Cost of sales—intellectual property licenses” based on the ratio of current revenues for the specific product to total projected revenues for all products in which the licensed property will be utilized. As intellectual property license contracts may extend for multiple years, the amortization of capitalized intellectual property license costs relating to such contracts may extend beyond one year. We evaluate the future recoverability of capitalized software development costs and intellectual property licenses on a quarterly basis. For products that have been released in prior periods, the primary evaluation criterion is actual title performance. For products that are scheduled to be released in future periods, recoverability is evaluated based on the expected performance of the specific products to which the costs relate or in which the licensed trademark or copyright is to be used. Criteria used to evaluate expected product performance include: historical performance of comparable products developed with comparable technology; orders for the product prior to its release; and, for any sequel product, estimated performance based on the performance of the product on which the sequel is based. Further, as many of our capitalized intellectual property licenses extend for multiple products over multiple years, we also assess the recoverability of capitalized intellectual property license costs based on certain qualitative factors, such as the success of other products and/or entertainment vehicles utilizing the intellectual property, whether there are any future planned theatrical releases or television series based on the intellectual property, and the rights holder's continued promotion and exploitation of the intellectual property. Significant management judgments and estimates are utilized in assessing the recoverability of capitalized costs. In evaluating the recoverability of capitalized costs, the assessment of expected product performance utilizes forecasted sales amounts and estimates of additional costs to be incurred. If revised forecasted or actual product sales are less than the originally forecasted amounts utilized in the initial recoverability analysis, the net realizable value may be lower than originally estimated in any given quarter, which could result in an impairment charge. Material differences may result in the amount and timing of expense for any period if management makes different judgments or utilizes different estimates in evaluating these qualitative factors.
Inventories	Inventories Inventories consist of materials (including manufacturing royalties paid to console manufacturers), labor and freight-in and are stated at the lower of cost (weighted average method) or net realizable value.
Property and equipment	Long-Lived Assets Property and Equipment. Property and equipment are recorded at cost and depreciated on a straight-line basis over the estimated useful life (i.e., 25 to 33 years, for buildings, and 2 to 5 years, for computer equipment, office furniture and other equipment) of the asset. When assets are retired or disposed of, the cost and accumulated depreciation thereon are removed and any resulting gains or losses are included in the consolidated statements of operations. Leasehold improvements are amortized using the straight-line method over the estimated life of the asset, not to exceed the length of the lease. Repair and maintenance costs are expensed as incurred.
Goodwill and Other Indefinite-Lived Assets	Goodwill and Other Indefinite-Lived Assets. We account for goodwill using the provisions within ASC Topic 350. Under ASC Topic 350, goodwill is considered to have an indefinite life, and is carried at cost. Acquired trade names are assessed as indefinite lived assets as there are no foreseeable limits on the periods of time over which they are expected to contribute cash flows. Goodwill and acquired trade names are not amortized, but are subject to an impairment test annually, as well as in between annual tests when events or circumstances indicate that the carrying value may not be recoverable. We perform our annual impairment testing at December 31st. Our annual goodwill impairment test is performed at the reporting unit level. We have determined our reporting units based on the guidance within ASC Subtopic 350-20, which provides that reporting units are generally operating segments or one reporting level below the operating segments. As of December 31, 2011, the Company’s reporting units are the same as our operating segments: Activision, Blizzard, and Distribution. We test goodwill for possible impairment by first determining the fair value of the related reporting unit and comparing this value to the recorded net assets of the reporting unit, including goodwill. In the event the recorded net assets of the reporting unit exceed the estimated fair value of such assets, we perform a second step to measure the amount of the impairment, which is equal to the amount by which the recorded goodwill exceeds the implied fair value of the goodwill after assessing the fair value of each of the assets and liabilities within the reporting unit. Fair value of our reporting units is determined using an income approach based on discounted cash flow models. In determining the fair value of our reporting units, we assumed a discount rate between 10.0% and 13.0%. During our 2011 annual impairment testing, the Company identified and recorded a $12 million impairment of goodwill to “General and administrative” in the statement of operations related to the Distribution reporting unit. The impairment was due to declines in our expected future performance of the distribution companies based on growing industry trends towards digital distribution and online gaming. The estimated fair values of the remaining reporting units exceeded their carrying values by at least $4 billion or 40% as of December 31, 2011. However, changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.
Goodwill and Other Indefinite-Lived Assets	We test acquired trade names for possible impairment by using a discounted cash flow model to estimate fair value. We have determined that no impairment has occurred at December 31, 2011 based upon a set of assumptions regarding discounted future cash flows, which represent our best estimate of future performance at this time. In determining the fair value of our trade names, we assumed a discount rate of 10%, and royalty saving rates of approximately 1.5%. A one percentage point increase in the discount rate would not yield an impairment charge to our trade names. Changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.
Amortizable Intangible Assets	Amortizable Intangible Assets. Intangible assets subject to amortization are carried at cost less accumulated amortization, and amortized over the estimated useful life in proportion to the economic benefits received. Management evaluates the recoverability of our identifiable intangible assets and other long-lived assets in accordance with FASB guidance within ASC Subtopic 360-10, which generally requires the assessment of these assets for recoverability when events or circumstances indicate a potential impairment exists. We considered certain events and circumstances in determining whether the carrying value of identifiable intangible assets and other long-lived assets may not be recoverable including, but not limited to: significant changes in performance relative to expected operating results; significant changes in the use of the assets; significant negative industry or economic trends; a significant decline in our stock price for a sustained period of time; and changes in our business strategy. In determining whether an impairment exists, we estimate the undiscounted cash flows to be generated from the use and ultimate disposition of these assets. If an impairment is indicated based on a comparison of the assets’ carrying values and the undiscounted cash flows, the impairment loss is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. In the fourth quarter of 2010, we recorded impairment charges of $67 million, $9 million and $250 million to license agreements, game engines and internally developed franchises intangible assets, respectively. In the fourth quarter of 2009, we recorded impairment charges of $24 million, $12 million and $373 million to license agreements, game engines and internally developed franchises intangible assets, respectively. (See Note 11 of the Notes to Consolidated Financial Statements)
Revenue Recognition	Revenue Recognition Revenue Arrangements with Multiple Deliverables Effective January 1, 2011, we adopted amendments to an accounting standard related to revenue recognition for arrangements with multiple deliverables (which standard, as amended, is referred to herein as the “new accounting principles”). The new accounting principles establish a selling price hierarchy for determining the selling price of a deliverable and requires the application of the relative selling price method to allocate the consideration received for an arrangement to each deliverable in a multiple deliverables revenue arrangement. Certain of our revenue arrangements have multiple deliverables and, as such, are accounted for under the new accounting principles. These revenue arrangements include product sales consisting of both software and hardware deliverables (such as peripherals or other ancillary collectors' items sold together with physical “boxed” software) and our sales of World of Warcraft boxed products, expansion packs and value-added services, each of which is considered with the related subscription services for these purposes. Our assessment of deliverables and units of accounting does not change under the new accounting principles. Pursuant to the guidance of ASU 2009-13, when a revenue arrangement contains multiple elements, such as hardware and software products, licenses and/or services, we allocate revenue to each element based on a selling price hierarchy. The selling price for a deliverable is based on its vendor-specific-objective-evidence (“VSOE”) if it is available, third-party evidence (“TPE”) if VSOE is not available, or best estimated selling price (“BESP”) if neither VSOE nor TPE is available. In multiple element arrangements where more-than-incidental software deliverables are included, revenue is allocated to each separate unit of accounting for each of the non-software deliverables and to the software deliverables as a group using the relative selling prices of each of the deliverables in the arrangement based on the aforementioned selling price hierarchy. If the arrangement contains more than one software deliverable, the arrangement consideration allocated to the software deliverables as a group is then allocated to each software deliverable using the guidance for recognizing software revenue. As noted above, when neither VSOE nor TPE is available for a deliverable, we use BESP. We do not have significant revenue arrangements that require BESP for the year ended December 31, 2011. The inputs we use to determine the selling price of our significant deliverables include the actual price charged by the Company for a deliverable that the Company sells separately, which represents the VSOE, and the wholesale prices of the same or similar products, which represents TPE. The pattern and timing of revenue recognition for deliverables and allocation of the arrangement consideration did not change upon the adoption of the new accounting principles. Also, the adoption of the new accounting standard has not had a material impact on our financial statements in the current period. Product Sales We recognize revenue from the sale of our products once title and risk of loss have been transferred to our customers and any performance obligation(s) have been completed. Certain products are sold to customers with a “street date” (which is the earliest date these products may be sold by retailers). For these products, we recognize revenue on the later of the street date and the date the product is sold to the customer. Revenue from product sales is recognized after deducting the estimated allowance for returns and price protection. For our software products with online functionality, we evaluate whether those features or functionality are more than an inconsequential separate deliverable in addition to the software product. This evaluation is performed for each software product and any online transaction, such as a digital download of a title or product add-ons, when it is released. When we determine that a software title contains online functionality that constitutes a more-than-inconsequential separate deliverable in addition to the product, principally because of its importance to gameplay, we consider our performance obligations for this title to extend beyond the sale of the game. VSOE of fair value does not exist for the online functionality of some products, as we do not separately charge for this component of every title. As a result, we recognize all of the software-related revenue from the sale of any such title ratably over the estimated service period of such title. In addition, we initially defer the costs of sales for the title (excluding intangible asset amortization), and recognize the costs of sales as the related revenues are recognized. Cost of sales includes manufacturing costs, software royalties and amortization, and intellectual property licenses costs. We recognize revenues from World of Warcraft boxed product, expansion packs and value-added services, in each case with the related subscription service revenue, ratably over the estimated service period beginning upon activation of the software and delivery of the related services. Revenues attributed to the sale of World of Warcraft boxed software and related expansion packs are classified as “Product sales”, whereas revenues attributable to subscriptions and other value-added services are classified as “Subscription, licensing and other revenues”. Revenues for software products with more-than-inconsequential separate service deliverables and World of Warcraft products are recognized over the estimated service periods, which range from a minimum of five months to a maximum of less than a year. For our software products with features we consider to be incidental to the overall product offering and an inconsequential deliverable, such as products which provide limited online features at no additional cost to the consumer, we recognize the related revenue from them upon the transfer of title and risk of loss of the product to our customer. With respect to online transactions, such as online downloads of titles or product add-ons that do not include a more-than-inconsequential separate service deliverable, revenue is recognized when the fee is paid by the online customer to purchase online content, the product is available for download and is activated for gameplay. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable. Sales incentives and other consideration given by us to our customers, such as rebates and product replacement fees, are considered adjustments of the selling price of our products and are reflected as reductions to revenue. Sales incentives and other consideration that represent costs incurred by us for assets or services received, such as the appearance of our products in a customer's national circular ad, are reflected as sales and marketing expenses when the benefit from the sales incentive is separable from sales to the same customer and we can reasonably estimate the fair value of the benefit. Subscription Revenues Subscription revenues are derived from World of Warcraft and from our Call of Duty Elite membership. World of Warcraft is a game that is playable through Blizzard's servers and is generally sold through a subscription-only basis, whereas Call of Duty Elite provides an enhanced multiplayer gameplay experience through subscription-based services, such as monthly downloadable content and year round competitions. For World of Warcraft, after the first month of free usage that is included with the World of Warcraft boxed software, the World of Warcraft end user may enter into a subscription agreement for additional future access. Revenues associated with the sale of subscriptions via boxed software and prepaid subscription cards, as well as prepaid subscriptions sales, are deferred until the subscription service is activated by the consumer and are then recognized ratably over the subscription period. Value-added service revenues associated with subscriptions are recognized ratably over the estimated service periods. Licensing Revenues Third-party licensees in Russia, China and Taiwan distribute and host Blizzard's World of Warcraft game in their respective countries under license agreements, for which they pay the Company a royalty. We recognize these royalties as revenues based on the end users' activation of the underlying prepaid time, if all other performance obligations have been completed, or based on usage by the end user, when we have continuing service obligations. We recognize any upfront licensing fee received over the term of the contracts. With respect to license agreements that provide customers the right to make multiple copies in exchange for guaranteed amounts, revenue is generally recognized upon delivery of a master copy. Per copy royalties on sales that exceed the guarantee are recognized as earned. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable. Breakage Revenues World of Warcraft boxed product sales and subscription revenues are recognized upon activation of the game. We analyze historical activation patterns over time to determine when the likelihood of activation ever occurring becomes remote. We recognize revenues from subscriptions that have not yet been activated, prepaid subscription cards, as well as prepaid subscription sales, when the likelihood of future activation occurring is remote (defined as “breakage revenues”). For the years ended December 31, 2011, 2010, and 2009, we recorded $0 million, $14 million, and $5 million, respectively of breakage revenues from the sale of packaged software in product sales, and $0 million, $6 million, and $8 million, respectively of prepaid and subscription breakage revenues in subscription, licensing and other revenues in the consolidated statements of operations. Other Revenues Other revenues primarily include licensing activity of intellectual property other than software to third-parties. Revenue is recorded upon receipt of licensee statements, or upon the receipt of cash, provided the license period has begun.
Allowances for Returns, Price Protection, Doubtful Accounts, and Inventory Obsolescence	Allowances for Returns, Price Protection, Doubtful Accounts, and Inventory Obsolescence We closely monitor and analyze the historical performance of our various titles, the performance of products released by other publishers, market conditions, and the anticipated timing of other releases to assess future demand of current and upcoming titles. Initial volumes shipped upon title launch and subsequent reorders are evaluated with the goal of ensuring that quantities are sufficient to meet the demand from the retail markets, but at the same time are controlled to prevent excess inventory in the channel. We benchmark units to be shipped to our customers using historical and industry data. We may permit product returns from, or grant price protection to, our customers under certain conditions. In general, price protection refers to the circumstances in which we elect to decrease, on a short or longer term basis, the wholesale price of a product by a certain amount and, when granted and applicable, allow customers a credit against amounts owed by such customers to us with respect to open and/or future invoices. The conditions our customers must meet to be granted the right to return products or price protection include, among other things, compliance with applicable trading and payment terms, and consistent return of inventory and delivery of sales reporting to us. We may also consider other factors, including the facilitation of slow-moving inventory and other market factors. Significant management judgments and estimates must be made and used in connection with establishing the allowance for returns and price protection in any accounting period based on estimates of potential future product returns and price protection related to current period product revenue. We estimate the amount of future returns and price protection for current period product revenue utilizing historical experience and information regarding inventory levels and the demand and acceptance of our products by the end consumer. The following factors are used to estimate the amount of future returns and price protection for a particular title: historical performance of titles in similar genres; historical performance of the hardware platform; historical performance of the franchise; console hardware life cycle; sales force and retail customer feedback; industry pricing; weeks of on-hand retail channel inventory; absolute quantity of on-hand retail channel inventory; our warehouse on-hand inventory levels; the title's recent sales history (if available); marketing trade programs; and performance of competing titles. The relative importance of these factors varies among titles depending upon, among other items, genre, platform, seasonality, and sales strategy. Based upon historical experience, we believe that our estimates are reasonable. However, actual returns and price protection could vary materially from our allowance estimates due to a number of reasons including, among others, a lack of consumer acceptance of a title, the release in the same period of a similarly themed title by a competitor, or technological obsolescence due to the emergence of new hardware platforms. Material differences may result in the amount and timing of our revenue for any period if factors or market conditions change or if management makes different judgments or utilizes different estimates in determining the allowances for returns and price protection. For example, a 1% change in our December 31, 2011 allowance for sales returns, price protection and other allowances would have impacted net revenues by approximately $3 million. Similarly, management must make estimates as to the collectability of our accounts receivable. In estimating the allowance for doubtful accounts, we analyze the age of current outstanding account balances, historical bad debts, customer concentrations, customer creditworthiness, current economic trends, and changes in our customers' payment terms and their economic condition, as well as whether we can obtain sufficient credit insurance. Any significant changes in any of these criteria would affect management's estimates in establishing our allowance for doubtful accounts. We regularly review inventory quantities on-hand and in the retail channel. We write down inventory based on excess or obsolete inventories determined primarily by future anticipated demand for our products. Inventory write-downs are measured as the difference between the cost of the inventory and net realizable value, based upon assumptions about future demand, which are inherently difficult to assess and dependent on market conditions. At the point of a loss recognition, a new, lower cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established basis.
Shipping and Handling	Shipping and Handling Shipping and handling costs, which consist primarily of packaging and transportation charges incurred to move finished goods to customers, are included in “Cost of sales—product costs.”
Advertising Expenses	Advertising Expenses We expense advertising as incurred, except for production costs associated with media advertising, which are deferred and charged to expense when the related advertisement is ran for the first time. Advertising expenses for the years ended December 31, 2011, 2010, and 2009 were $343 million, $332 million, and $366 million, respectively, and are included in “Sales and marketing expense” in the consolidated statements of operations.
Income Taxes	Income Taxes We record a tax provision for the anticipated tax consequences of the reported results of operations. In accordance with FASB income tax guidance within ASC Topic 740, the provision for income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are recognized for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the deferred tax assets or liabilities are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We evaluate deferred tax assets each period for recoverability. For those assets that do not meet the threshold hold of “more likely than not” that they will be realized in the future, a valuation allowance is recorded. We report a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. We recognize interest and penalties, if any, related to unrecognized tax benefits in income tax expense.
Foreign Currency Translation	Foreign Currency Translation All assets and liabilities of our foreign subsidiaries are translated into U.S. dollars at the exchange rate in effect at the balance sheet date, and revenue and expenses are translated at average exchange rates during the period. The resulting translation adjustments are reflected as a component of “Accumulated other comprehensive income (loss)” in shareholders' equity.
Earnings (Loss) Per Common Share	Earnings (Loss) Per Common Share “Basic earnings (loss) per common share” is computed by dividing income (loss) available to common shareholders by the weighted average number of common shares outstanding for the periods presented. “Diluted earnings per share” is computed by dividing income (loss) available to common shareholders by the weighted average number of common shares outstanding, increased by the weighted average number of common stock equivalents. Common stock equivalents are calculated using the treasury stock method and represent incremental shares issuable upon exercise of our outstanding options. However, potential common shares are not included in the denominator of the diluted earnings (loss) per share calculation when inclusion of such shares would be anti-dilutive, such as in a period in which a net loss is recorded. When we determine whether instruments granted in stock-based payment transactions are participating securities, unvested stock-based awards which include the right to receive non-forfeitable dividends or dividend equivalents are considered to participate with common stock in undistributed earnings. With participating securities, we are required to calculate basic and diluted earnings per common share amounts under the two-class method. The two-class method excludes from earnings per common share calculations any dividends paid or owed to participating securities and any undistributed earnings considered to be attributable to participating securities.
Stock-Based Compensation	Stock-Based Compensation We account for stock-based compensation in accordance with ASC Topic 718-10, Compensation-Stock Compensation, and ASC Subtopic 505-50, Equity-Based Payments to Non-Employees (“ASC stock-based compensation guidance”). Stock-based compensation expense recognized during the requisite services period (that is, the period for which the employee is being compensated) and is based on the value of stock-based payment awards after reduction for estimated forfeitures. Forfeitures are estimated at the time of grant and are revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Stock-based compensation expense recognized in the consolidated statement of operations for the years ended December 31, 2011, 2010, and 2009 included both compensation expense for stock- based payment awards granted by Activision, Inc. prior to, but not yet vested as of July 9, 2008, based on the revalued fair value estimated at July 9, 2008, and compensation expense for the stock-based payment awards granted by us subsequent to July 9, 2008. We estimate the value of stock-based payment awards on the measurement date using a binomial-lattice model. Our determination of fair value of stock-based payment awards on the date of grant using an option-pricing model is affected by our stock price as well as assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, our expected stock price volatility over the term of the awards, and actual and projected employee stock option exercise behaviors. We generally determine the fair value of restricted stock rights (including restricted stock units, restricted stock awards, and performance shares) based on the closing market price of the Company’s common stock on the date of grant. See Note 18 of the Notes to Consolidated Financial Statements.

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2011

Summary of significant accounting policies

The accompanying consolidated financial statements include the accounts and operations of the Company. All intercompany accounts and transactions have been eliminated. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”).

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates and assumptions.

Reclassifications

Certain reclassifications have been made to prior year amounts to conform to the current period presentation.

Subsequent Events

The Company considers events or transactions that occur after the balance sheet date, but before the financial statements are issued, to provide additional evidence relative to certain estimates or to identify matters that require additional disclosures.

Cash and cash equivalents

Cash and Cash Equivalents We consider all money market funds and highly liquid investments with maturities of three months or less at the time of purchase to be “Cash and cash equivalents”.

Investment securities

Investment Securities Investments designated as available-for-sale securities are carried at fair value, which is based on quoted market prices for such securities, if available, or is estimated on the basis of quoted market prices of financial instruments with similar characteristics. Unrealized gains and losses of the Company’s available-for-sale securities are excluded from earnings and reported as a component of “Other comprehensive income (loss)”. Investments with original maturities greater than 90 days and remaining maturities of less than one year are normally classified as “Short-term investments”. In addition, investments with maturities beyond one year may be classified as “Short-term investments” if they are highly liquid in nature and represent the investment of cash that is available for current operations. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in investment and other income, net in the consolidated statements of operations. The Company’s investments include auction rate securities (“ARS”). These ARS are variable rate bonds tied to short-term interest rates with long-term maturities. ARS have interest rates which reset through a modified Dutch auction at predetermined short-term intervals, typically every 7, 28, or 35 days. Interest on ARS is generally paid at the end of each auction process and is based upon the interest rate determined for the prior auction. The majority of our ARS are highly rated, and are typically collateralized by student loans guaranteed by the U.S. government under the Federal Family Education Loan Program or backed by monoline bond insurance companies.

Restricted cash - compensating balances

Restricted Cash—Compensating Balances Restricted cash is included within “Short-term investments” on the consolidated balance sheets. The majority of our restricted cash relates to a standby letter of credit required by one of our inventory manufacturers to qualify for certain payment terms on our inventory purchases. Under the terms of this arrangement, we are required to maintain with the issuing bank a compensating balance, restricted as to use, of not less than the sum of the available amount of the letter of credit plus the aggregate amount of any drawings under the letter of credit that have been honored thereunder, but have not yet been reimbursed.

Financial instruments

Financial Instruments The carrying amount of “Cash and cash equivalents”, “Accounts receivable”, “Accounts payable”, and “Accrued expenses” substantively approximate fair value due to the short-term nature of these accounts. Our U.S. treasuries, government agency securities, and mortgage-backed securities are carried at fair value, which is based on quoted market prices for such securities, if available, or is estimated on the basis of quoted market prices of financial instruments with similar characteristics. ARS are carried at fair value, which is estimated using an income-approach model (specifically, a discounted cash-flow analysis). Derivative instruments, primarily foreign exchange contracts, are reported at fair value in “Other assets” or “Other liabilities” in the consolidated balance sheet. The fair value of foreign currency contracts are estimated based on the prevailing exchange rates of the various hedged currencies as of the end of the period. Activision Blizzard transacts business in various foreign currencies and has significant international sales and expenses denominated in foreign currencies, subjecting us to foreign currency risk. We utilize foreign exchange forward contracts and swaps, with maturities of generally less than one year, to mitigate foreign currency exchange rate risk associated with foreign currency-denominated assets and liabilities. Activision Blizzard does not use derivatives for speculative or trading purposes, and the Company does not designate these derivatives as hedging instruments under ASC Topic 815. Accordingly, gains and losses resulting from changes in the fair values through the period are reported as General and administrative expenses or Investment and other income, net in the consolidated statements of operations, depending on the nature of the derivative.

Other-Than-Temporary Impairments

The Company regularly reviews its investments to determine whether a decline in fair value below the cost basis is other than a temporary impairment. If the decline is determined to be other-than-temporary, the cost basis of the investment is written down to fair value. For available-for-sale fixed maturity instruments where credit-related impairments exist, other-than-temporary impairments are reported in the consolidated statement of operations and non-credit impairments are reported in accumulated other comprehensive income (loss).

Software Development Costs and Intellectual Property Licenses

Software development costs include payments made to independent software developers under development agreements, as well as direct costs incurred for internally developed products.

We account for software development costs in accordance with the Financial Accounting Standards Board (“FASB”) guidance for the costs of computer software to be sold, leased, or otherwise marketed within ASC Subtopic 985-20. Software development costs are capitalized once technological feasibility of a product is established and such costs are determined to be recoverable. Technological feasibility of a product encompasses both technical design documentation and game design documentation, or the completed and tested product design and working model. Significant management judgments and estimates are utilized in the assessment of when technological feasibility is established. For products where proven technology exists, this may occur early in the development cycle. Technological feasibility is evaluated on a product-by-product basis. Prior to a product's release, we expense, as part of “Cost of sales—software royalties and amortization”, capitalized costs if and when we believe such amounts are not recoverable. Capitalized costs for those products that are cancelled or expected to be abandoned are charged to “Product development expense” in the period of cancellation. Amounts related to software development which are not capitalized are charged immediately to “Product development expense.”

Commencing upon product release, capitalized software development costs are amortized to “Cost of sales—software royalties and amortization” based on the ratio of current revenues to total projected revenues for the specific product, generally resulting in an amortization period of six months or less.

Intellectual property license costs represent license fees paid to intellectual property rights holders for use of their trademarks, copyrights, software, technology, music or other intellectual property or proprietary rights in the development of our products. Depending upon the agreement with the rights holder, we may obtain the right to use the intellectual property in multiple products over a number of years, or alternatively, for a single product. Prior to the related product's release, we expense, as part of “cost of sales—intellectual property licenses,” capitalized intellectual property costs when we believe such amounts are not recoverable. Capitalized intellectual property costs for those products that are cancelled or expected to be abandoned are charged to product development expense in the period of cancellation.

Commencing upon the related product's release, capitalized intellectual property license costs are amortized to “Cost of sales—intellectual property licenses” based on the ratio of current revenues for the specific product to total projected revenues for all products in which the licensed property will be utilized. As intellectual property license contracts may extend for multiple years, the amortization of capitalized intellectual property license costs relating to such contracts may extend beyond one year.

We evaluate the future recoverability of capitalized software development costs and intellectual property licenses on a quarterly basis. For products that have been released in prior periods, the primary evaluation criterion is actual title performance. For products that are scheduled to be released in future periods, recoverability is evaluated based on the expected performance of the specific products to which the costs relate or in which the licensed trademark or copyright is to be used. Criteria used to evaluate expected product performance include: historical performance of comparable products developed with comparable technology; orders for the product prior to its release; and, for any sequel product, estimated performance based on the performance of the product on which the sequel is based. Further, as many of our capitalized intellectual property licenses extend for multiple products over multiple years, we also assess the recoverability of capitalized intellectual property license costs based on certain qualitative factors, such as the success of other products and/or entertainment vehicles utilizing the intellectual property, whether there are any future planned theatrical releases or television series based on the intellectual property, and the rights holder's continued promotion and exploitation of the intellectual property.

Significant management judgments and estimates are utilized in assessing the recoverability of capitalized costs. In evaluating the recoverability of capitalized costs, the assessment of expected product performance utilizes forecasted sales amounts and estimates of additional costs to be incurred. If revised forecasted or actual product sales are less than the originally forecasted amounts utilized in the initial recoverability analysis, the net realizable value may be lower than originally estimated in any given quarter, which could result in an impairment charge. Material differences may result in the amount and timing of expense for any period if management makes different judgments or utilizes different estimates in evaluating these qualitative factors.

Inventories

Inventories consist of materials (including manufacturing royalties paid to console manufacturers), labor and freight-in and are stated at the lower of cost (weighted average method) or net realizable value.

Property and equipment

Long-Lived Assets

Property and Equipment. Property and equipment are recorded at cost and depreciated on a straight-line basis over the estimated useful life (i.e., 25 to 33 years, for buildings, and 2 to 5 years, for computer equipment, office furniture and other equipment) of the asset. When assets are retired or disposed of, the cost and accumulated depreciation thereon are removed and any resulting gains or losses are included in the consolidated statements of operations. Leasehold improvements are amortized using the straight-line method over the estimated life of the asset, not to exceed the length of the lease. Repair and maintenance costs are expensed as incurred.

Goodwill and Other Indefinite-Lived Assets

Goodwill and Other Indefinite-Lived Assets. We account for goodwill using the provisions within ASC Topic 350. Under ASC Topic 350, goodwill is considered to have an indefinite life, and is carried at cost. Acquired trade names are assessed as indefinite lived assets as there are no foreseeable limits on the periods of time over which they are expected to contribute cash flows. Goodwill and acquired trade names are not amortized, but are subject to an impairment test annually, as well as in between annual tests when events or circumstances indicate that the carrying value may not be recoverable. We perform our annual impairment testing at December 31st. Our annual goodwill impairment test is performed at the reporting unit level. We have determined our reporting units based on the guidance within ASC Subtopic 350-20, which provides that reporting units are generally operating segments or one reporting level below the operating segments. As of December 31, 2011, the Company’s reporting units are the same as our operating segments: Activision, Blizzard, and Distribution. We test goodwill for possible impairment by first determining the fair value of the related reporting unit and comparing this value to the recorded net assets of the reporting unit, including goodwill. In the event the recorded net assets of the reporting unit exceed the estimated fair value of such assets, we perform a second step to measure the amount of the impairment, which is equal to the amount by which the recorded goodwill exceeds the implied fair value of the goodwill after assessing the fair value of each of the assets and liabilities within the reporting unit. Fair value of our reporting units is determined using an income approach based on discounted cash flow models. In determining the fair value of our reporting units, we assumed a discount rate between 10.0% and 13.0%. During our 2011 annual impairment testing, the Company identified and recorded a $12 million impairment of goodwill to “General and administrative” in the statement of operations related to the Distribution reporting unit. The impairment was due to declines in our expected future performance of the distribution companies based on growing industry trends towards digital distribution and online gaming. The estimated fair values of the remaining reporting units exceeded their carrying values by at least $4 billion or 40% as of December 31, 2011. However, changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.

Goodwill and Other Indefinite-Lived Assets

We test acquired trade names for possible impairment by using a discounted cash flow model to estimate fair value. We have determined that no impairment has occurred at December 31, 2011 based upon a set of assumptions regarding discounted future cash flows, which represent our best estimate of future performance at this time. In determining the fair value of our trade names, we assumed a discount rate of 10%, and royalty saving rates of approximately 1.5%. A one percentage point increase in the discount rate would not yield an impairment charge to our trade names. Changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.

Amortizable Intangible Assets

Amortizable Intangible Assets. Intangible assets subject to amortization are carried at cost less accumulated amortization, and amortized over the estimated useful life in proportion to the economic benefits received. Management evaluates the recoverability of our identifiable intangible assets and other long-lived assets in accordance with FASB guidance within ASC Subtopic 360-10, which generally requires the assessment of these assets for recoverability when events or circumstances indicate a potential impairment exists. We considered certain events and circumstances in determining whether the carrying value of identifiable intangible assets and other long-lived assets may not be recoverable including, but not limited to: significant changes in performance relative to expected operating results; significant changes in the use of the assets; significant negative industry or economic trends; a significant decline in our stock price for a sustained period of time; and changes in our business strategy. In determining whether an impairment exists, we estimate the undiscounted cash flows to be generated from the use and ultimate disposition of these assets. If an impairment is indicated based on a comparison of the assets’ carrying values and the undiscounted cash flows, the impairment loss is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. In the fourth quarter of 2010, we recorded impairment charges of $67 million, $9 million and $250 million to license agreements, game engines and internally developed franchises intangible assets, respectively. In the fourth quarter of 2009, we recorded impairment charges of $24 million, $12 million and $373 million to license agreements, game engines and internally developed franchises intangible assets, respectively. (See Note 11 of the Notes to Consolidated Financial Statements)

Revenue Recognition

Revenue Arrangements with Multiple Deliverables

Effective January 1, 2011, we adopted amendments to an accounting standard related to revenue recognition for arrangements with multiple deliverables (which standard, as amended, is referred to herein as the “new accounting principles”). The new accounting principles establish a selling price hierarchy for determining the selling price of a deliverable and requires the application of the relative selling price method to allocate the consideration received for an arrangement to each deliverable in a multiple deliverables revenue arrangement. Certain of our revenue arrangements have multiple deliverables and, as such, are accounted for under the new accounting principles. These revenue arrangements include product sales consisting of both software and hardware deliverables (such as peripherals or other ancillary collectors' items sold together with physical “boxed” software) and our sales of World of Warcraft boxed products, expansion packs and value-added services, each of which is considered with the related subscription services for these purposes. Our assessment of deliverables and units of accounting does not change under the new accounting principles.

Pursuant to the guidance of ASU 2009-13, when a revenue arrangement contains multiple elements, such as hardware and software products, licenses and/or services, we allocate revenue to each element based on a selling price hierarchy. The selling price for a deliverable is based on its vendor-specific-objective-evidence (“VSOE”) if it is available, third-party evidence (“TPE”) if VSOE is not available, or best estimated selling price (“BESP”) if neither VSOE nor TPE is available. In multiple element arrangements where more-than-incidental software deliverables are included, revenue is allocated to each separate unit of accounting for each of the non-software deliverables and to the software deliverables as a group using the relative selling prices of each of the deliverables in the arrangement based on the aforementioned selling price hierarchy. If the arrangement contains more than one software deliverable, the arrangement consideration allocated to the software deliverables as a group is then allocated to each software deliverable using the guidance for recognizing software revenue.

As noted above, when neither VSOE nor TPE is available for a deliverable, we use BESP. We do not have significant revenue arrangements that require BESP for the year ended December 31, 2011. The inputs we use to determine the selling price of our significant deliverables include the actual price charged by the Company for a deliverable that the Company sells separately, which represents the VSOE, and the wholesale prices of the same or similar products, which represents TPE. The pattern and timing of revenue recognition for deliverables and allocation of the arrangement consideration did not change upon the adoption of the new accounting principles. Also, the adoption of the new accounting standard has not had a material impact on our financial statements in the current period.

Product Sales

We recognize revenue from the sale of our products once title and risk of loss have been transferred to our customers and any performance obligation(s) have been completed. Certain products are sold to customers with a “street date” (which is the earliest date these products may be sold by retailers). For these products, we recognize revenue on the later of the street date and the date the product is sold to the customer. Revenue from product sales is recognized after deducting the estimated allowance for returns and price protection.

For our software products with online functionality, we evaluate whether those features or functionality are more than an inconsequential separate deliverable in addition to the software product. This evaluation is performed for each software product and any online transaction, such as a digital download of a title or product add-ons, when it is released.

When we determine that a software title contains online functionality that constitutes a more-than-inconsequential separate deliverable in addition to the product, principally because of its importance to gameplay, we consider our performance obligations for this title to extend beyond the sale of the game. VSOE of fair value does not exist for the online functionality of some products, as we do not separately charge for this component of every title. As a result, we recognize all of the software-related revenue from the sale of any such title ratably over the estimated service period of such title. In addition, we initially defer the costs of sales for the title (excluding intangible asset amortization), and recognize the costs of sales as the related revenues are recognized. Cost of sales includes manufacturing costs, software royalties and amortization, and intellectual property licenses costs.

We recognize revenues from World of Warcraft boxed product, expansion packs and value-added services, in each case with the related subscription service revenue, ratably over the estimated service period beginning upon activation of the software and delivery of the related services. Revenues attributed to the sale of World of Warcraft boxed software and related expansion packs are classified as “Product sales”, whereas revenues attributable to subscriptions and other value-added services are classified as “Subscription, licensing and other revenues”.

Revenues for software products with more-than-inconsequential separate service deliverables and World of Warcraft products are recognized over the estimated service periods, which range from a minimum of five months to a maximum of less than a year.

For our software products with features we consider to be incidental to the overall product offering and an inconsequential deliverable, such as products which provide limited online features at no additional cost to the consumer, we recognize the related revenue from them upon the transfer of title and risk of loss of the product to our customer.

With respect to online transactions, such as online downloads of titles or product add-ons that do not include a more-than-inconsequential separate service deliverable, revenue is recognized when the fee is paid by the online customer to purchase online content, the product is available for download and is activated for gameplay. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable.

Sales incentives and other consideration given by us to our customers, such as rebates and product replacement fees, are considered adjustments of the selling price of our products and are reflected as reductions to revenue. Sales incentives and other consideration that represent costs incurred by us for assets or services received, such as the appearance of our products in a customer's national circular ad, are reflected as sales and marketing expenses when the benefit from the sales incentive is separable from sales to the same customer and we can reasonably estimate the fair value of the benefit.

Subscription Revenues

Subscription revenues are derived from World of Warcraft and from our Call of Duty Elite membership. World of Warcraft is a game that is playable through Blizzard's servers and is generally sold through a subscription-only basis, whereas Call of Duty Elite provides an enhanced multiplayer gameplay experience through subscription-based services, such as monthly downloadable content and year round competitions.

For World of Warcraft, after the first month of free usage that is included with the World of Warcraft boxed software, the World of Warcraft end user may enter into a subscription agreement for additional future access. Revenues associated with the sale of subscriptions via boxed software and prepaid subscription cards, as well as prepaid subscriptions sales, are deferred until the subscription service is activated by the consumer and are then recognized ratably over the subscription period. Value-added service revenues associated with subscriptions are recognized ratably over the estimated service periods.

Licensing Revenues

Third-party licensees in Russia, China and Taiwan distribute and host Blizzard's World of Warcraft game in their respective countries under license agreements, for which they pay the Company a royalty. We recognize these royalties as revenues based on the end users' activation of the underlying prepaid time, if all other performance obligations have been completed, or based on usage by the end user, when we have continuing service obligations. We recognize any upfront licensing fee received over the term of the contracts.

With respect to license agreements that provide customers the right to make multiple copies in exchange for guaranteed amounts, revenue is generally recognized upon delivery of a master copy. Per copy royalties on sales that exceed the guarantee are recognized as earned. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable.

Breakage Revenues

World of Warcraft boxed product sales and subscription revenues are recognized upon activation of the game. We analyze historical activation patterns over time to determine when the likelihood of activation ever occurring becomes remote. We recognize revenues from subscriptions that have not yet been activated, prepaid subscription cards, as well as prepaid subscription sales, when the likelihood of future activation occurring is remote (defined as “breakage revenues”). For the years ended December 31, 2011, 2010, and 2009, we recorded $0 million, $14 million, and $5 million, respectively of breakage revenues from the sale of packaged software in product sales, and $0 million, $6 million, and $8 million, respectively of prepaid and subscription breakage revenues in subscription, licensing and other revenues in the consolidated statements of operations.

Other Revenues

Other revenues primarily include licensing activity of intellectual property other than software to third-parties. Revenue is recorded upon receipt of licensee statements, or upon the receipt of cash, provided the license period has begun.

Allowances for Returns, Price Protection, Doubtful Accounts, and Inventory Obsolescence

We closely monitor and analyze the historical performance of our various titles, the performance of products released by other publishers, market conditions, and the anticipated timing of other releases to assess future demand of current and upcoming titles. Initial volumes shipped upon title launch and subsequent reorders are evaluated with the goal of ensuring that quantities are sufficient to meet the demand from the retail markets, but at the same time are controlled to prevent excess inventory in the channel. We benchmark units to be shipped to our customers using historical and industry data.

We may permit product returns from, or grant price protection to, our customers under certain conditions. In general, price protection refers to the circumstances in which we elect to decrease, on a short or longer term basis, the wholesale price of a product by a certain amount and, when granted and applicable, allow customers a credit against amounts owed by such customers to us with respect to open and/or future invoices. The conditions our customers must meet to be granted the right to return products or price protection include, among other things, compliance with applicable trading and payment terms, and consistent return of inventory and delivery of sales reporting to us. We may also consider other factors, including the facilitation of slow-moving inventory and other market factors.

Significant management judgments and estimates must be made and used in connection with establishing the allowance for returns and price protection in any accounting period based on estimates of potential future product returns and price protection related to current period product revenue. We estimate the amount of future returns and price protection for current period product revenue utilizing historical experience and information regarding inventory levels and the demand and acceptance of our products by the end consumer. The following factors are used to estimate the amount of future returns and price protection for a particular title: historical performance of titles in similar genres; historical performance of the hardware platform; historical performance of the franchise; console hardware life cycle; sales force and retail customer feedback; industry pricing; weeks of on-hand retail channel inventory; absolute quantity of on-hand retail channel inventory; our warehouse on-hand inventory levels; the title's recent sales history (if available); marketing trade programs; and performance of competing titles. The relative importance of these factors varies among titles depending upon, among other items, genre, platform, seasonality, and sales strategy.

Based upon historical experience, we believe that our estimates are reasonable. However, actual returns and price protection could vary materially from our allowance estimates due to a number of reasons including, among others, a lack of consumer acceptance of a title, the release in the same period of a similarly themed title by a competitor, or technological obsolescence due to the emergence of new hardware platforms. Material differences may result in the amount and timing of our revenue for any period if factors or market conditions change or if management makes different judgments or utilizes different estimates in determining the allowances for returns and price protection. For example, a 1% change in our December 31, 2011 allowance for sales returns, price protection and other allowances would have impacted net revenues by approximately $3 million.

Similarly, management must make estimates as to the collectability of our accounts receivable. In estimating the allowance for doubtful accounts, we analyze the age of current outstanding account balances, historical bad debts, customer concentrations, customer creditworthiness, current economic trends, and changes in our customers' payment terms and their economic condition, as well as whether we can obtain sufficient credit insurance. Any significant changes in any of these criteria would affect management's estimates in establishing our allowance for doubtful accounts.

We regularly review inventory quantities on-hand and in the retail channel. We write down inventory based on excess or obsolete inventories determined primarily by future anticipated demand for our products. Inventory write-downs are measured as the difference between the cost of the inventory and net realizable value, based upon assumptions about future demand, which are inherently difficult to assess and dependent on market conditions. At the point of a loss recognition, a new, lower cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established basis.

Shipping and Handling

Shipping and handling costs, which consist primarily of packaging and transportation charges incurred to move finished goods to customers, are included in “Cost of sales—product costs.”

Advertising Expenses

We expense advertising as incurred, except for production costs associated with media advertising, which are deferred and charged to expense when the related advertisement is ran for the first time. Advertising expenses for the years ended December 31, 2011, 2010, and 2009 were $343 million, $332 million, and $366 million, respectively, and are included in “Sales and marketing expense” in the consolidated statements of operations.

Income Taxes

We record a tax provision for the anticipated tax consequences of the reported results of operations. In accordance with FASB income tax guidance within ASC Topic 740, the provision for income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are recognized for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the deferred tax assets or liabilities are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We evaluate deferred tax assets each period for recoverability. For those assets that do not meet the threshold hold of “more likely than not” that they will be realized in the future, a valuation allowance is recorded.

We report a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. We recognize interest and penalties, if any, related to unrecognized tax benefits in income tax expense.

Foreign Currency Translation

All assets and liabilities of our foreign subsidiaries are translated into U.S. dollars at the exchange rate in effect at the balance sheet date, and revenue and expenses are translated at average exchange rates during the period. The resulting translation adjustments are reflected as a component of “Accumulated other comprehensive income (loss)” in shareholders' equity.

Earnings (Loss) Per Common Share

“Basic earnings (loss) per common share” is computed by dividing income (loss) available to common shareholders by the weighted average number of common shares outstanding for the periods presented. “Diluted earnings per share” is computed by dividing income (loss) available to common shareholders by the weighted average number of common shares outstanding, increased by the weighted average number of common stock equivalents. Common stock equivalents are calculated using the treasury stock method and represent incremental shares issuable upon exercise of our outstanding options. However, potential common shares are not included in the denominator of the diluted earnings (loss) per share calculation when inclusion of such shares would be anti-dilutive, such as in a period in which a net loss is recorded.

When we determine whether instruments granted in stock-based payment transactions are participating securities, unvested stock-based awards which include the right to receive non-forfeitable dividends or dividend equivalents are considered to participate with common stock in undistributed earnings. With participating securities, we are required to calculate basic and diluted earnings per common share amounts under the two-class method. The two-class method excludes from earnings per common share calculations any dividends paid or owed to participating securities and any undistributed earnings considered to be attributable to participating securities.

Stock-Based Compensation

Stock-Based Compensation We account for stock-based compensation in accordance with ASC Topic 718-10, Compensation-Stock Compensation, and ASC Subtopic 505-50, Equity-Based Payments to Non-Employees (“ASC stock-based compensation guidance”). Stock-based compensation expense recognized during the requisite services period (that is, the period for which the employee is being compensated) and is based on the value of stock-based payment awards after reduction for estimated forfeitures. Forfeitures are estimated at the time of grant and are revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Stock-based compensation expense recognized in the consolidated statement of operations for the years ended December 31, 2011, 2010, and 2009 included both compensation expense for stock- based payment awards granted by Activision, Inc. prior to, but not yet vested as of July 9, 2008, based on the revalued fair value estimated at July 9, 2008, and compensation expense for the stock-based payment awards granted by us subsequent to July 9, 2008. We estimate the value of stock-based payment awards on the measurement date using a binomial-lattice model. Our determination of fair value of stock-based payment awards on the date of grant using an option-pricing model is affected by our stock price as well as assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, our expected stock price volatility over the term of the awards, and actual and projected employee stock option exercise behaviors. We generally determine the fair value of restricted stock rights (including restricted stock units, restricted stock awards, and performance shares) based on the closing market price of the Company’s common stock on the date of grant. See Note 18 of the Notes to Consolidated Financial Statements.