Sadly this doesn't work on steam deck, the game doesn't scale, control commands are off the screen and the sound glitches. I've tried different proton layers, launch commands, full screen, windowed, gamescope etc all to no avail. Works on a PC but if you want to play chess on the go get a different program. Would I recommend, PC version is boiled down but ok, on deck it's a none starter. It's a shame because it still works with my DGT board, which would have made it really cool on deck, shame the implementation is so bad. As a long time Fritz fan, I'll probably swerve their next release too until they get a better customer focus.