Chess vs ComputerFree, no sign-up

You play White and move first; players take turns making one move. Attack the opponent's king so it has no escape and it's checkmate — you win. Pawns move forward and capture diagonally, knights jump in an L shape, bishops move diagonally, rooks move straight, the queen does both, and the king moves one square in any direction.

Yes. You can castle only if neither the king nor the rook has moved, the squares between them are empty, and the king isn't attacked on the square it starts on, passes through or lands on (move the king two squares and the rook follows automatically). En passant is allowed only on the move right after an enemy pawn advances two squares: capture it by moving diagonally onto the square it skipped. A pawn that reaches the last rank promotes to a queen, rook, bishop or knight of your choice.

Stalemate (no legal moves while not in check), the same position appearing three times, the 50-move rule (50 moves by each side with no pawn move or capture), and insufficient material (such as king vs king, or king and one knight, when neither side can checkmate). Draws and losses are not recorded.

Easy looks 2 moves ahead and Normal looks 4 moves ahead, then follows every capture to the end. It scores positions by material and piece placement, and in the endgame it drives your king to the edge of the board. On the same day and level it always answers the same moves the same way, which is how the server can replay and verify your game.

Only wins are recorded, scored as 200 minus your number of moves. Highest score first; ties go to the shorter time. You only need a nickname, and you can submit up to 30 times a day per level. The server replays your game, including the computer's replies, to verify it.