Checkers

The board. Eight rows by eight columns, with alternating light and dark squares. Pieces only sit on dark squares. You play the black pieces at the bottom; the computer plays the red pieces at the top.

Moving. A piece moves one square diagonally forward to an empty dark square. Click your piece to select it, then click any highlighted square to move there. Click a different piece to switch selection.

Capturing. Jump over an adjacent enemy piece diagonally to the empty square just beyond it; the jumped piece is captured. If a capture is available anywhere on the board, you must capture — non-capturing pieces won't be selectable. After a capture, if more captures are available from the new square, the chain continues automatically; you must take all jumps in the chain.

Kings. A man that reaches the opponent's back row promotes to a king and gains a crown. Kings move and capture diagonally in all four directions. If a man promotes during a multi-jump chain, the chain ends — standard American rules.

Winning. You win when the computer has no legal moves (no pieces left, or all remaining pieces blocked). You lose under the same condition.

Difficulty. The Level chips control the computer's search depth: Easy looks 2 moves ahead, Medium 5, Hard 8, Expert 12. Higher levels take longer to respond.

Hint. The Hint button names the move the computer would play if it were you, at the current difficulty. It never moves the piece for you.

Undo. Undo backs up your last move and the computer's reply together, returning to the position before your last decision.