choosing illegal moves

[PotatMuffin]

it would be possible to look through all the pieces on the board and just choose a move (that isn't legal) that removes the opponents queen or one of their rooks. the rules also do not state that this is not allowed.

[SebLague]

I've updated the rules to mention that cheating at chess is not allowed :)

[mcthouacbb]

This doesn't seem to be a problem. ChallengeController.OnMoveChosen validates whether the move is legal, and an illegal move counts as an automatic instant win for the opponent