Dota 2 Vulkan Support Is Now Available
Valve pushed out the update this afternoon that provides opt-in support for using the Vulkan graphics API of the Source 2 Engine rather than using OpenGL (or DirectX under Windows). Those interested in trying out Vulkan on Dota 2 can enable the Dota 2 Vulkan DLC and launch the game with the -vulkan switch.
Under Linux the Dota 2 Vulkan support is for the GeForce 600 series and newer with the 364.16 proprietary driver and AMD GCN 1.2 (e.g. Radeon R9 285 Tonga / Radeon R9 Fury Fiji cards) with the new AMDGPU-PRO hybrid driver. It appears that Intel's Vulkan Linux driver isn't yet supported by this game.
More details on this early Vulkan support for Dota 2, the second AAA game supporting Vulkan on Linux, can be found via this Dota2.com announcement.