The deal is described as Microsoft's largest ever and means that the two companies are now merging.
Activision Blizzard is behind successful game titles such as World of Warcraft and Call of Duty, while a couple of years ago the Swedish company King was acquired with the successful game Candy Crush.
Microsoft in turn is behind the Xbox game console and the deal is seen as a way to strengthen the company's position in competition with competitor Sony with the Playstation console.
Criticized CEO continues
Activision Blizzard has at the same time recently been heavily criticized after reports in the Wall Street Journal, among others, about abuse of employees and a corporate culture that has disadvantaged female employees for several years.
An employee is said to have stated, among other things, that she was raped on several occasions by one of her managers in connection with various company parties, something that, among others, CEO Bobby Kotick is said to have silenced.
In connection with the deal, it is now stated that Kotick will continue in its role as CEO.