Antichess

Antichess is the inverted variant. The objective is to lose: a player who has no pieces left, or who is stalemated with no legal move, wins. The mechanics that produce the inversion are simple — captures are compulsory, and the king is treated as an ordinary piece — but the consequences run through every aspect of play and produce a game that looks like chess and plays like a logic puzzle.

The variant has been studied computationally to an unusual depth. Antichess starting from the standard initial position is a solved game: with perfect play from both sides, White wins by playing 1.e3. The 2016 solution by Mark Watkins, after years of cooperative analysis on the Lichess community, established the result definitively for one specific opening move and demonstrated that no other White first move has been proven to win. Despite the solution, the game remains widely played online because human calculation cannot reproduce the perfect-play tree in a real game.

The rules

The basic rules of chess apply with the following changes:

1. Win condition is inverted. The player who first runs out of pieces or moves wins. Stalemate is a win for the stalemated player.
2. Captures are forced. If any capture is available, the player must play one. If multiple captures are available, the choice is free among them.
3. The king is not royal. There is no check, no checkmate, no castling. The king can be captured like any other piece, and a player can leave their own king attacked without consequence.
4. Pawn promotion includes the king as a legal promotion choice (since the king is no longer special), in addition to the usual queen, rook, bishop, and knight.
5. Draws occur by threefold repetition or the 50-move rule, as in standard chess.

The strategic shape

The compulsory-capture rule transforms the game into a sequence of forced moves whenever both sides have captures available. Strong play involves creating positions in which the opponent’s only captures are bad for them — typically because each forced capture chains into another capture that costs them material faster than it costs you.

Sacrifices in antichess are not sacrifices; they are gifts the opponent is forced to accept. The art is constructing positions where the gift initiates a chain that strips the opponent down faster than yourself. The middlegame revolves around piece geometry that maximises capture chains, and the endgame is technical in a way that looks nothing like standard chess: a lone king pursued by a queen is a win for the king’s side, because the queen will eventually be forced into a capture that loses it.

Where to play

Lichess maintains a continuous antichess rating pool and runs frequent tournaments at blitz time controls. Chess.com offers antichess on its variants page. Standard practice is 3+0 or 5+0 blitz; longer time controls are uncommon because positions clarify quickly. The strongest antichess specialists play at a level even strong classical-chess grandmasters can find difficult to match — the calculation patterns of the inverted game do not transfer easily from standard chess.