Chess basics

The board and the pieces

A chessboard is an 8×8 grid: the pieces stand on the squares, not on the intersections.

White moves first and Black sits opposite. Each side has 16 pieces: 8 pawns, 2 rooks, 2 knights, 2 bishops, 1 queen and 1 king.

You can click the board below. Click a white piece and every square it can move to is marked, with the pieces it can capture ringed.

Those squares are not hard-coded by me: the same engine the game uses calculates them, including castling, en passant and promotion.

The bottom-right square is always light. That is a rule, not a layout choice.

How each piece moves

Each example comes as a pair: first how the piece normally moves, then what changes when the restriction applies.

The number under each card is calculated by the engine on the spot, not counted by me.

Winning, losing and a few special rules

Check and checkmate

If the next move could take the opponent's king, that is check. The side in check must answer it: move the king away, take the attacking piece, or block the line.

If none of the three is possible, it is checkmate and that side loses.

Ignoring a check is not a foul, it is simply impossible: the engine never generates such a move, so you cannot play one in the game.

Castling

Castling moves the king and a rook together: the king goes two squares towards the rook and the rook jumps to the king's other side. It counts as the king's move, not the rook's.

There are three conditions: neither the king nor that rook has moved, the squares between them are empty, and neither the square the king passes over nor the one it lands on is attacked.

En passant

When an enemy pawn goes two squares from its starting position and passes over a square your pawn could capture on, you may move diagonally as usual and take that pawn.

That right lasts only for the very next move; after that it is gone.

Promotion

A pawn that reaches the last rank must become a queen, rook, bishop or knight. You may choose any of them, even one that is still on the board.

So in theory you can have three queens at once — in practice it is almost always a queen.

Draws and stalemate

If the side to move has no legal move and its king is not in check, that is stalemate and the game is drawn. This is the opposite of xiangqi, where being stuck means losing.

Other draws: the same position occurring three times, fifty moves in a row with no capture and no pawn move, or too little material left to deliver checkmate.

A few opening ideas

• Take the center first: the middle files and the four central squares are reached by the most pieces, so start by putting pawns and knights there.
• Develop knights early: a knight in the corner has only two squares, but eight in the center, so it usually moves before a bishop.
• Castle early: castling hides the king in a corner and brings a rook towards the center — usually the best value move in the opening.
• Do not bring the queen out too early: while small pieces chase her around, you are handing the opponent free moves.
• Do not grab pawns: winning a pawn in the opening while your king stays in the middle usually costs more than it gains.

Want to play? Start a chess game against the computer at five levels, or two people taking turns on one device.