Antichess

In Antichess, the usual objective of chess is reversed. Under the international-style rules used by Lichess, you win by getting rid of all your pieces or by reaching your turn with no legal move. Giving your own pieces to the opponent can therefore be desirable.

The rule that dominates play is that capturing is compulsory. If at least one legal capture exists, you may not choose a non-capturing move. If several captures are available, you may choose which one to make. Many moves are therefore designed to force the opponent to capture a particular piece.

The king loses its special royal status. It can be captured like an ordinary piece, there is no check or checkmate, and there is no castling. Under Lichess rules, a pawn may even promote to a king. Because check does not exist, moving a king onto an attacked square does not have the illegal meaning it has in standard chess.

The name Antichess covers several closely related but not identical rule traditions. Some implementations handle stalemate, meaning having no legal move, differently. It is therefore worth checking the exact rules when a platform distinguishes Antichess, Losing Chess, Giveaway, or related names.