Checkers

Checkers (English draughts) on an 8 by 8 board. You play Black and move first. WOPR plays White and looks several moves ahead before each reply.

Start it

wopr checkers

Or log on, type LIST GAMES, and pick number 6 from the list. It also answers to 6 and draughts.

Click or tap a screenshot to see it larger.

Win by leaving WOPR with no legal move, usually by taking all its pieces. If each side makes 40 moves with no capture and no man moving, the game is a draw.
Men move one square diagonally forward. At YOUR MOVE: type the man’s square, then the square it moves to: C3-D4 or C3D4. WOPR answers with a line such as WOPR: B6-C5.
You must jump when you can. Type C3XE5 to jump, and C3XE5XG7 to jump twice. When a jump can continue in more than one way, WOPR lists the ways after THE JUMP GOES ON:.
A man that reaches the far row becomes a king, shown as a capital B or W. A king moves both ways. Crowning ends the move.
The board brackets the last move’s squares and marks each man it jumped with x. Type RESIGN to give up.

You type	What it does
`C3-D4 or C3D4`	move from C3 to D4 (a space between the squares works too)
`C3XE5 or C3E5`	jump from C3 over D4 to E5
`C3XE5XG7`	jump twice. When the jump can continue in only one way, the first hop alone is enough
`RESIGN`	give up the game
`Esc, Esc`	leave the game and return to WOPR

Keep the men on your back row (row 1) at home as long as you can. WOPR’s men must reach that row to become kings, and your men there block the squares.
Use forced jumps. WOPR must jump when it can, just as you must. So you can offer a man to pull a white piece onto a square that gives you a double jump.
When you are ahead, trade men. With fewer pieces on the board, your extra man is worth more.
For an easier game, run it with a seed (wopr checkers -s 1). WOPR then looks 6 moves ahead, counting both sides’ moves, instead of up to 10.