Both sides pick a move in secret and play them at the same time.
How to play
Each round you (White) and the bot pick a move in secret from the same position, then both are revealed and played at once. If a piece moves off a square the enemy targeted, it dodges (pieces may even swap places). If both pieces land on the same square they collide: the more valuable piece survives (equal pieces both die). Capture the enemy king to win; if both kings fall it's a draw. Pawns promote to queens; no castling or en passant. 50 rounds in a row without a capture or a pawn move is a draw.