Title text:
The draw-by-repetition rule does a good job of keeping players from sliding a tile back and forth repeatedly, but the tiles definitely introduce some weird en passant and castling edge cases.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3139/
This could be a real thing: at each turn, you can either make a standard chess move, or slide one of the board tiles … who wants to code it up?