Rocket Checkers

What is Rocket Checkers?

Rocket Checkers is a complete game of checkers, also known as English draughts, that runs in your browser. Play against the computer at four levels, from Cadet, which makes beginner mistakes, to Admiral, which reads many moves ahead, or pass the screen to a friend. Tap a piece to see where it can go, then tap or drag it there.

The real rules are built in: captures are compulsory, multi-jumps must be finished, a piece that reaches the far row is crowned king and ends its move, and kings move and capture both ways. A side with no pieces or no legal moves loses, and games are drawn by threefold repetition or forty moves each without a capture or a plain piece moving. Undo takes back your last move, Hint suggests one, and the game is saved in your browser so a closed tab costs you nothing.

How to play Rocket Checkers

1. Choose your opponent (Computer or Friend on the same screen), the computer's level and your colour (Red, White or Random), then tap New game. Red always moves first.
2. Tap one of your pieces: dots mark the squares it can move to. Tap a dot or drag the piece there.
3. Ordinary pieces (men) move one square diagonally forward onto an empty dark square. To capture, jump diagonally over an enemy piece onto the empty square directly behind it; the jumped piece is removed.
4. If you can capture, you must, and the pieces that can capture are highlighted. When a jump lands where another jump is possible, keep going in the same turn; if there is a choice of route, tap each landing square in turn.
5. Reach the far row to be crowned king. A king moves and captures one square diagonally in any direction. Win by taking every enemy piece or leaving the other side with no legal move.

Rocket Checkers tips and strategy

• Keep your back row filled as long as you can; it stops the other side from crowning kings.
• Pieces in the centre have more options than pieces on the edges, and edge pieces can only move or be attacked in one direction.
• Because captures are forced, you can offer one piece to pull an enemy piece into a double jump of your own. Watch for the same trick being played on you.
• Move in groups. A piece that runs ahead on its own is easy to trap, while pieces backing each other up cannot be jumped.
• When you're ahead, trade pieces one for one: a two-piece lead is far stronger when only a few pieces are left.
• Get a king early if you can, then bring it back to attack enemy men from behind, where they can't turn to face it.

The four computer levels

Cadet (level 1) looks two half-moves ahead and often picks a weaker move on purpose, so new players can win. Pilot (level 2) looks four half-moves ahead with a little randomness. Commander (level 3) reads eight half-moves ahead with no randomness and punishes loose pieces. Admiral (level 4) searches as deep as it can in about a second and a half per move, which is many moves ahead in most positions.

The computer always follows capture sequences to the end before judging a position, and it runs in a background thread so the page stays responsive. The Hint button uses the Commander search for you, whatever level you are playing.

Checkers rules explained

Rocket Checkers plays English draughts, the version called checkers in North America: an 8 by 8 board, play on the dark squares only, and twelve pieces for each side on the three rows nearest each player. Red moves first and the players then alternate, one move per turn.

Men move one square diagonally forward. Captures are made by jumping over an adjacent enemy piece to the empty square beyond, and they are compulsory: if any of your pieces can capture, you must capture. If several different captures are available you may choose any of them, even one that takes fewer pieces, but once you start a jump sequence you must complete it. A man that reaches the far row during a jump is crowned and its move ends there, even if a further jump would otherwise be possible.

Kings move one square diagonally in any direction and can jump forwards and backwards, including several times in one turn. You lose if all your pieces are captured or if you have no legal move on your turn, which happens when your remaining pieces are blocked. The game is a draw if the same position occurs three times with the same player to move, or if forty moves pass for each side with no capture and no move by an uncrowned man. Only legal moves are offered, so you can never break a rule by accident.

Strategy by skill level

Beginners: play against Cadet and concentrate on not giving pieces away. Before each move, look at every square around the piece you are moving and the square it leaves behind, and ask whether your opponent can jump. Keep two or three pieces on your back row to block kings.

Improving players: Pilot will punish loose pieces more often. Learn to use the forced-capture rule as a weapon by offering a piece that drags an enemy man onto a square where you get a double jump in return. Control the centre squares, keep your pieces connected, and avoid emptying one side of the board.

Experienced players: Commander and Admiral calculate deeply, so plan ahead: keep spare safe moves in reserve so you are never forced to break up a strong formation, and avoid running out of moves on one side of the board. In endgames, an extra king is usually enough to win, because two kings can corner and trap a single king, while equal numbers of kings usually mean a draw. Use the material shown beside the board to decide when to trade.

Reading checkers notation

The move list uses standard checkers notation. The 32 playable squares are numbered 1 to 32, starting at Red's home row, so Red's pieces start on squares 1 to 12 and White's on 21 to 32. A simple move is written with a dash, as in 11-15. A capture is written with an x, and multi-jumps list every landing square, as in 15x24x31. Because the notation is standard, you can follow published checkers openings and problems on the board.

Checkers, draughts and other versions

Checkers and draughts are names for the same family of games. The 8 by 8 version with kings that move one square at a time is the standard game in Britain, Ireland and North America, and was written about in detail in William Payne's book on draughts in 1756. In 2007 a team at the University of Alberta, led by Jonathan Schaeffer, showed with their program Chinook that this version is a draw with perfect play by both sides.

Other countries play different rules. International draughts uses a 10 by 10 board with twenty pieces each, men that can capture backwards, flying kings that move any distance along a diagonal, and a rule that you must take the largest possible number of pieces. Russian and Brazilian draughts use the 8 by 8 board but also have flying kings and backward captures by men. If you learned one of those versions, expect kings here to be slower and men to capture only forwards.

Controls, phones and keyboard play

Rocket Checkers works with a mouse, a touch screen or a keyboard. On a phone or tablet, tap a piece and then tap its destination, or drag it; Full screen gives the board as much space as possible. With a keyboard, use the arrow keys to move around the board, Enter or Space to pick up and place a piece, and Escape to let go of a selected piece. The status line tells you whose turn it is and when you must capture or keep jumping. Against the computer, your wins, losses and draws are recorded under the move list.

Rocket Checkers FAQ