Changes

Announced on August 21st, 2018, Proton is based on [[Wine]] and includes additional components like the wrappers [https://github.com/doitsujin/dxvk DXVK ] (which translates Direct3D 9, 10 and 11 calls to Vulkan on-the-fly), [https://github.com/HansKristian-Work/vkd3d-proton vkd3d-proton ] (which translates Direct3D 12 to Vulkan), and [https://github.com/FNA-XNA/FAudio FAudio ] (an XAudio reimplementation). As a rework of Steam Play, it avoids having to set up an additional Steam installation for Wine, which used to be the only way to get Windows-only Steam games working on Linux.

Proton is included in the Steam Linux client by default , and Valve whitelists [https://steamdb.info/app/891390/info/ over 100 games] known to work out-of-the-box.<ref name="protonannouncement">https://steamcommunity.com/games/221410/announcements/detail/1696055855739350561</ref> However, by changing a switch in Steam's settings, Proton can be enabled for all Windows games even if they don't currently work.<ref group=N>To do this, click Steam > Settings > Steam Play > "Enable Steam Play for all titles".</ref> Proton can also be force-enabled per-game to run the Windows version of games that already have a Linux port on Steam.<ref name="force-enable">https://steamcommunity.com/groups/SteamClientBeta#announcements/detail/1703951108827819236</ref> In addition to Steam's Linux client, Proton also comes included in Valve's own Linux distro SteamOS, which is designed for dedicated PC gaming systems, such as Valve's [https://www.steamdeck.com/en/ Steam Deck].

As of mid-2021, the only games that still don't work with Proton are mostly multiplayer games that use third-party anti-cheat systems.<ref group=N>This is because anti-cheats rely on kernel functions that cannot be recreated by Wine due to the very low level of access they provide.</ref> However, Valve seems to be working on a solution for running third-party anticheat anti-cheat systems on the Steam Deck, which may be extended to other Linux distros in the future.<ref>Sean Hollister (September 24, 2021). [https://www.theverge.com/2021/9/23/22690670/epic-eac-anti-cheat-linux-valve-steam-deck-support-games One of the Steam Deck’s biggest hurdles just disappeared: EAC has come to Linux and BattlEye is inbound]. The Verge.</ref>

* [https://www.protondb.com/ ProtonDB] - User -reported compatibility list.