Dota 2 is dropping support for 32-bit systems

Dota 2 is dropping support for some older hardware in the coming months, including older 32-bit operating systems. As part of their announcement of the update leading up to The International 10, Valve said they're dropping some of the older hardware that Dota has supported up until now. "In order to keep the game and the Source 2 engine fresh, we're planning on removing support for some older systems and configurations. Nothing is changing today, but in the coming months we'll implement the following changes," said Valve.

Those changes include dropping support for Dota on 32-bit systems, macOS versions below 10.14, support for DirectX 9 in favor of DirectX 11, support for OpenGL in favor of Vulkan, and support for XAudio in favor of SDL Audio. 

"Removing these older technologies will let us streamline our development efforts as well as use the newer features of these APIs to provide an even better Dota experience," says Valve's announcement.

It's probably a calculated decision, seeing as Valve has access to a lot of information about what an average gaming rig is via the Steam hardware surveys. Microsoft started dropping 32-bit Windows sales last year, though it still supports the installations that have existed until now. MacOS 10.14, for comparison, released in 2018.