The change in our goodwill balance is as follows:


	Total
Balance at March 31, 2022	$	674.6
Acquisition of Zynga (see Note 20)	5,994.4
Acquisition of Popcore (see Note 20)	72.1
Additions from immaterial acquisitions	26.5
Currency translation adjustment	(0.5)
Balance at March 31, 2023	$	6,767.1
Impairment	(2,342.1)
Additions from immaterial acquisitions	9.7
Currency translation adjustment	(8.3)
Balance at March 31, 2024	$	4,426.4

During the fiscal year ended March 31, 2024, we recognized goodwill impairment charges of $2,342.1, representing a partial impairment related to one of our reporting units. We identified various qualitative factors that, collectively, indicated that the fair value of one of our reporting units was more likely than not less than its carrying amount, including a reduction in the forecasted performance of the reporting unit due to industry conditions and changes in our strategies for games within the reporting unit in response to those conditions. As a result of this qualitative analysis, we performed a valuation of the reporting unit using discounted cash flow and guideline public company methodologies. Key assumptions and estimates used in deriving the fair value are forecasted revenue, EBITDA margins, long-term growth rate, and discount rate. There were no goodwill impairment charges for the fiscal years ended March 31, 2023 and March 31, 2022.

The following table sets forth the intangible assets that are subject to amortization:


	March 31,
	2024						2023
	Gross Carrying Amount		Accumulated Amortization		Net Book Value		Gross Carrying Amount		Accumulated Amortization		Net Book Value		Weighted average useful life
Developed Game Technology	$	3,788.8	$	(1,301.4)	$	2,487.4	$	4,434.5	$	(744.0)	$	3,690.5	7 years
Branding and Trade Names	395.1		(68.5)		326.6		395.2		(33.1)		362.1		12 years
Game Engine Technology	322.5		(147.3)		175.2		323.2		(73.5)		249.7		4 years
User Base	319.2		(319.2)		—		319.2		(274.4)		44.8		0 years
Developer Relationships	57.0		(26.5)		30.5		57.0		(12.2)		44.8		5 years
Advertising Technology	43.0		(26.6)		16.4		43.0		(12.3)		30.7		3 years
Customer Relationships	31.0		(11.5)		19.5		31.0		(5.3)		25.7		5 years
Intellectual Property	27.5		(23.1)		4.4		22.3		(18.2)		4.1		6 years
In Place Lease	2.0		(1.4)		0.6		1.9		(1.1)		0.8		4 years
Analytics Technology	30.1		(30.1)		—		30.1		(30.1)		—		0 years
Total intangible assets	$	5,016.2	$	(1,955.6)	$	3,060.6	$	5,657.4	$	(1,204.2)	$	4,453.2

Amortization of intangible assets, including impairments, is included in our Consolidated Statements of Operations as follows:


	Fiscal Year Ended March 31,
	2024		2023		2022
Cost of revenue	$	1,303.5	$	1,171.5	$	52.0
Selling and marketing	51.0		277.1		5.3
Research and development	28.7		24.6		5.5
Depreciation and amortization	35.7		33.5		2.0
Total amortization of intangible assets	$	1,418.9	$	1,506.7	$	64.8

During the fiscal year ended March 31, 2024, we recorded impairment charges of $577.4 for acquisition-related Developed Game Technology intangible assets within Cost of revenue as a result of a reduction in the forecasted performance of certain games due to industry conditions and changes in our strategies for certain games in response to those conditions. During the fiscal year ended March 31, 2023, we recorded impairment charges of $465.3 for acquisition-related Developed Game Technology intangible assets within Cost of revenue as a result of (i) a reduction in the forecasted performance of certain games due to macroeconomic conditions and changes in our strategies for those games and (ii) our decision not to proceed with further development of a certain interactive entertainment software product. The fair value of those intangible assets was measured using the multi-period excess earnings method, consistent with the approach used at acquisition. Key assumptions and estimates used in deriving the fair value are forecasted revenue, EBITDA margins, long-term decay rates, and discount rates. During the fiscal year ended March 31, 2022, there were no impairment charges for intangible assets.

Estimated future amortization of intangible assets that will be recorded in Cost of revenue and operating expenses for the years ending March 31, are as follows:


Fiscal Year Ended March 31,	Amortization
2025	$	706.4
2026	681.6
2027	620.1
2028	579.5
2029	234.7