To learn auto racing or acrobatic flying, there's the esports for engineers package of classic PC simulation games: https://github.com/bencaddigan/esports-for-engineers

I was recently learning to play go using gnugo[1].

[1] https://www.gnu.org/software/gnugo/

The book "Deep Learning and the game of Go" from Manning walks you through the process of building an AlphaGo clone using python and standard machine learning libraries.

https://github.com/maxpumperla/deep_learning_and_the_game_of...

Play a demo Go bot developed in the book here: https://www.badukai.com/demos/static/play_predict_19.html

to learn contract bridge, I find the bcalc single/double dummy solver bcalc useful: http://bcalc.w8.pl/index.php?lang=en&topic=download

also good is the freeware bride program Wbridge5, which has won several world computer bridge championships. It is a Windows program, but runs fine on linux with the wine emulation layer. (I've run it on fedora 30, debian 10 and ubuntu 19.10)

to learn chess, there's scid and the stockfish engine included in distros such as debian and ubuntu.

There's also the lc0 engine, which is the open source version of the mighty Deep Mind AlphaZero chess engine - linux installation instructions for lc0 are here: https://github.com/LeelaChessZero/lc0/blob/master/README.md

Also shoutout to lichess.org which is by far the best platform to play chess on and is completely free.

Free as in speech[0] and beer too!

[0] - https://github.com/lichess-org