How to play Checkers

Jump and crown your way to victory in classic draughts against a computer that hunts for every capture.

Checkers — draughts, in Britain — is played on the dark squares of an eight-by-eight board with twelve pieces a side. The rules fit in a paragraph and the game does not, which is the whole appeal. Everything below is the English draughts ruleset this version plays.

The board and the move

Only the dark squares are ever used, so a piece spends the entire game on its own colour. You take the teal pieces at the bottom and move up the board; the computer takes violet and moves down.

An ordinary piece moves one square diagonally forward to an empty square. It may never move backwards, never move sideways, and never move onto an occupied square. That is the whole of ordinary movement.

Capturing, and why it is compulsory

If an enemy piece sits diagonally in front of one of yours and the square directly beyond it is empty, you jump over it and remove it from the board.

Captures are compulsory. If any capture is available to you anywhere on the board, you must make one — you are not allowed to quietly develop instead. You may choose which capture to make when several are on offer, but you must make one of them.

If the piece you have just jumped with can immediately jump again from its new square, the turn continues and it must keep jumping until it can jump no more. This is a multiple jump, and it is where games are won: three enemy pieces left carelessly spaced can vanish in a single move.

Compulsory capture is the rule that turns checkers from a race into a game of traps. Because your opponent has no choice about taking, you can offer a piece knowing exactly what the reply will be, and set up the position you actually want two moves later. Giving up a piece to win two back is not a sacrifice here, it is the standard tool of the game.

Kings

Reach the far back row and your piece is crowned a King on the spot. That ends the turn even if the newly crowned King could jump again.

A King moves and captures one square diagonally in any of the four directions, backwards as well as forwards. It is not restricted to forward movement in any way, and that freedom makes it worth roughly two ordinary pieces in practice. Most close games are decided by who gets the first King.

Winning

You win by capturing every enemy piece, or by leaving your opponent with no legal move at all. The second is a real win condition rather than a technicality: a player whose remaining pieces are all blocked has lost even with pieces still on the board.

The three strengths

The computer searches ahead rather than following a script, and the setting changes how far. Easy looks a move or two out and will miss a plan. Medium sees ordinary traps coming. Hard will trade pieces off when it is ahead and grind the endgame out, which is exactly what a strong human does and exactly what beginners find hardest to play against.

Whichever setting you choose, the computer never misses a capture that is available to it, because captures are compulsory for it too.

Controls

Tap a piece to select it — its legal squares light up — then tap a highlighted square to move.

Red dots mark forced captures, which you must take.
Set the computer's strength with Easy / Medium / Hard.

Strategy tips

Keep your back row intact as long as you can. Those four squares are the only thing stopping an enemy piece from crowning, and every one you move forward is a door left open.
Advance in connected groups rather than sending one piece ahead. A piece with a friendly piece diagonally behind it cannot be jumped without an immediate recapture, which usually means it is not jumped at all.
Count the trade before you take. Compulsory capture means you can predict your opponent's reply exactly, so work out the whole exchange to its end rather than taking the first piece on offer.
Offer a piece deliberately to break up a strong formation. Giving one to win two back is the standard tool of checkers, not a desperate measure.
Take the centre columns early. Pieces in the middle have more squares to move to; pieces stuck on the edges have half the options and are the first to run out of moves.
Race for the first King. A King is worth roughly two ordinary pieces because it can move backwards, and in a close game whoever crowns first usually wins.
When you are ahead on material, trade pieces at every fair opportunity. Fewer pieces on the board magnifies an advantage; a crowded board hides it.
When you are behind, do the opposite and keep the board full. Complicated positions give your opponent more chances to go wrong, and a simplified endgame with fewer pieces is where a material deficit becomes fatal.