The rulebook.

Chess is played by two: White and Black. Each side has 16 pieces. The goal is to checkmate the opponent’s king: it is attacked and has no way left to escape (checkmate).

The king is never actually captured – the game ends before that. A game can also end without a winner, which is called a draw (all the ways to draw). And if you see no chance any more, you may resign at any time.

White always moves first, then the players take turns (how to move here).

The board has 64 squares, 8 × 8, alternately light and dark. The columns are called files (a to h), the rows ranks (1 to 8). So every square has a name, like e4 – more under notation.

Two rules of thumb for setting up:

• Light on the right: the bottom right square is light for both players.
• The queen goes on her own colour: the white queen on the light square d1, the black queen on the dark square d8. The kings stand next to them on e1 and e8.

On the back rank, from the outside in: rook, knight, bishop, and queen and king in the middle. The eight pawns stand in front of them.

Here on the site the board is always set up correctly. F flips it.

White starts, then each side makes exactly one move in turn. You can’t pass – not even when every possible move is bad.

How to move here: click one of your pieces. Dots show the squares it may go to, a ring shows a piece it can capture. Then click the target square. The keyboard works too: arrow keys move a cursor, Enter picks a piece up and puts it down. Or you type the move (notation).

Over the board the touch-move rule applies: if you touch one of your pieces, you have to move it. Online there is no such rule. Here you can select a piece and still change your mind; the move only counts once the piece is on its new square.

The server doesn’t allow illegal moves at all. If a move doesn’t work, your king is usually in check or the piece is pinned.

If a piece moves to a square occupied by an enemy piece, that piece is captured: it leaves the board, and the capturing piece takes its square. Capturing is optional – unlike in draughts, you never have to.

• You can’t capture your own pieces.
• Every piece captures the way it moves. The exception is the pawn: it moves straight ahead but captures diagonally forward.
• The king is never captured – it is checkmated.
• There is one special case: en passant.

Here on the site the captured pieces are shown next to the players’ names.

When a king is attacked – meaning an enemy piece could capture it on the next move – it is in check. You don’t have to announce it; here the king’s square turns red.

If you are in check, you must end it at once. There are exactly three ways:

1. Move away: the king moves to a square that is not attacked.
2. Capture: the attacking piece is captured – by any of your pieces, even by the king if the attacker is not protected.
3. Block: a piece steps between the king and the attacker. That doesn’t work against a knight, or when the attacker stands right next to the king.

No other moves are allowed then. If two pieces attack at once (double check), only moving the king helps. If there’s no way out, it is checkmate.

Also, you may never make a move that leaves your own king in check. That’s why pieces can be pinned.

“Why can’t I move my knight?” – that’s the most common question at the start. Usually the piece is pinned.

A piece is pinned when it stands on a straight or diagonal line between its own king and an enemy queen, rook or bishop. If it moved away, the king would be in check – and that is never allowed. So it may not move away.

Example: the white king is on e1, a white knight on e3, a black rook on e8. The knight shields the king from the rook. Every knight move would open the e-file – so the knight can’t move at all.

• A pinned piece may move along the line as long as it keeps shielding the king. A pinned rook on the e-file may move along the e-file and even capture the attacking rook. A knight never can.
• A pinned piece still attacks: the enemy king may not step onto a square it threatens.
• If the piece behind it is not the king but, say, the queen, it’s called a relative pin. Moving is allowed, but it often costs the queen.

Here on the site, when you click a pinned piece it only shows the squares that are still allowed – often none.

Every square has a name made of file (a–h) and rank (1–8), for example e4. A move is written as the piece’s letter followed by the target square.

Typing a move: next to the board you can type moves, / jumps there. The field understands e4, Nf3 (and the German Sf3), O-O and 0-0 – and always simply the start and target square: e2e4. You can leave out x, + and #.

The move list here shows small piece symbols instead of letters.

The king is the most important piece: if it is checkmated, the game is lost. It moves one square in any direction, straight or diagonal.

• It may never move to a square attacked by an enemy piece. That’s why the two kings can never stand right next to each other.
• Once per game it may castle together with a rook.

Letter: K.

The queen is the strongest piece. It moves as far as it likes, straight and diagonally – like a rook and a bishop combined. It can’t jump over other pieces.

Letter: Q (in German D for Dame).

The rook moves straight – horizontally or vertically – as far as it likes, but not over other pieces. If an enemy piece is in the way, it can capture it.

Together with the king it takes part in castling. Letter: R (in German T for Turm).

The bishop moves diagonally as far as it likes, but not over other pieces. So it always stays on the same colour: each side has one bishop for the light squares and one for the dark squares.

Letter: B (in German L for Läufer).

The knight moves in an “L”: two squares straight, then one to the side. It is the only piece that jumps over others, whether they are its own or the opponent’s. It only captures on the square where it lands.

With every move it changes square colour. A check by a knight can’t be blocked (check).

Letter: N (because K is taken by the king; in German S for Springer).

Pawns only move forward, one square straight ahead, and never back.

• Double step: while a pawn is still on its starting square (White on the 2nd, Black on the 7th rank), it may also advance two squares, if both are empty.
• Capturing: pawns capture differently from how they move – one square diagonally forward. If a piece stands directly in front of a pawn, the pawn is blocked.
• Plus two special rules: en passant and promotion on the last rank.

Pawns have no letter in notation: e4 means “pawn to e4”.

Castling is the only move in which two pieces move at once: king and rook. It brings the king to safety and the rook into play. Each side may castle once per game.

• Short castling (O-O): the king goes two squares towards the h-rook, from e1 to g1, and the rook jumps over it to f1. For Black: king e8–g8, rook h8–f8.
• Long castling (O-O-O): the king goes two squares towards the a-rook, from e1 to c1, and the rook from a1 to d1. For Black: king e8–c8, rook a8–d8.

You may only castle if

• neither the king nor that rook has moved yet in this game,
• all squares between them are empty,
• your king is not in check right now,
• and the king doesn’t cross or land on an attacked square.

The rook, on the other hand, may be attacked; in long castling so may b1 (or b8), which only the rook passes.

How to do it here: move the king two squares to the side – the rook follows by itself. Or type O-O or O-O-O; zeros work too (0-0).

A special rule for pawns; the name is French for “in passing”.

If a pawn makes a double step and lands right next to an enemy pawn, that pawn may capture it as if it had moved only one square: it moves diagonally onto the skipped square, and the pawn beside it disappears.

• This is possible only on the very next move. If you don’t do it right away, you lose the right.
• Only pawns can capture and be captured en passant.
• So for White it only works with a pawn on the 5th rank, for Black on the 4th.

How to do it here: click your pawn, the diagonal square is marked. Typed: exd6 or e5d6.

When a pawn reaches the last rank (White the 8th, Black the 1st), it is promoted at once: to a queen, rook, bishop or knight of its own colour – only king and pawn are not possible. It doesn’t matter what has been captured; you can have a second queen.

Almost always you take the queen. Rarely something else is better, like a knight that gives check at once, or a rook so the game doesn’t end in stalemate.

How to do it here: move the pawn to the last rank, and “Promote to …” opens. Choose with a click or Q R B N (the German D T L S work too). Typed: e8Q or e8=Q; without a letter it becomes a queen.

If the king is in check and there is no legal move that ends it – no moving away, no capturing, no blocking –, it is checkmate. The game is over at once; whoever gives checkmate wins.

Here the server detects checkmate by itself and ends the game. In notation it is written #.

Mind the difference to stalemate: having no move left without being in check is not a win but a draw.

If the side to move is not in check but has no legal move at all, it is stalemate. The game ends at once in a draw – even if the other side has far more pieces.

So be careful when you are well ahead: leave the enemy king a square until you can checkmate. Here the server detects stalemate by itself.

A game can also end without a winner. These are the ways to a draw:

• Stalemate: the side to move has no move but is not in check.
• The same position three times.
• Fifty-move rule: 50 moves without a pawn move or a capture.
• Insufficient material: nobody can checkmate any more.
• Agreement: one player offers a draw, the other accepts.
• Time ran out, but the other player can’t possibly checkmate.

The server detects the first four by itself and ends the game. A draw counts as half a point for each player.

When the same position appears on the board for the third time, the game is a draw. The repetitions don’t have to come one after another.

“The same position” means: the same pieces on the same squares, the same side to move and the same possibilities – for example whether castling or capturing en passant is still possible.

A typical case is perpetual check: one side keeps giving check, the king can’t escape, and the positions repeat.

In tournaments you have to claim this draw. Here the server detects the third repetition by itself and ends the game.

When both sides have made 50 moves in a row without any pawn move or capture, the game is a draw.

The rule prevents endless play when nobody makes progress. So if you want to win, you have to checkmate in time. Every pawn move and every capture restarts the count.

In tournaments you have to claim this draw. Here the server ends the game by itself after 50 such moves.

If neither side can checkmate the other king any more, however they play, the game ends in a draw. Here the server detects these cases by itself:

• king against king,
• king and one bishop or one knight against king,
• only kings and bishops, all standing on squares of the same colour.

With a pawn, a rook or a queen there is always enough material. King and two knights against king is not one of these cases: mate is possible there, if only after a mistake – the game goes on.

You may resign at any time if you see no chance any more. The game is then over at once, and your opponent has won. In chess that is polite and common – nobody has to play on until checkmate.

How to do it here: click Resign or press A and confirm with Y. Against the computer you can also take back a move instead.

Both players can agree to a draw at any time. Here is how, in games against humans:

• Click Draw or press R. Your opponent sees the offer and can accept (Y) or decline (N).
• The offer stands until the next move. If your opponent simply moves, it’s gone.
• If both offer a draw, it is agreed.

There are no draw offers against the computer. There you can resign or simply start a new game.

When you create a game, you choose:

• Classic: no clock. Everyone thinks as long as they like.
• Timed: each player has their own time of 1 to 180 minutes. It only runs while it’s their move. On top comes an increment of 0 to 60 seconds, added after every move. “5 + 3” means 5 minutes plus 3 seconds per move.
• Correspondence: over days, without a clock (more).

The clock starts only after White’s first move. It runs on the server, not in your browser – even if you leave the page. What happens when it runs out is explained under time ran out.

In tournaments, whoever runs out of time loses – unless the opponent can’t possibly checkmate any more, then it’s a draw. Here the game pauses first, and you decide:

• The player with time left can take the win on time (S). But if they only have their king left, alone or with a single bishop or knight, they can’t checkmate – then it’s a draw.
• Play on without clock (W): if both agree, the game continues as a classic game. The computer always agrees.
• The player who ran out of time can resign (A).

A correspondence game runs over days instead of minutes, without a clock. You move whenever it suits you and continue on any device.

• You need an account, also to accept an invitation. The game belongs to your account, not to the browser.
• My games shows where it’s your move.
• If a player doesn’t move for 14 days, the opponent can claim the win in the game.
• An invitation nobody accepts expires after 14 days.

Offering a draw and resigning work as in any other game.

In timed games the clock runs on the server. So it keeps running when you leave the page, switch tabs or lose the connection. There is no pause.

When you come back, the page fetches the current state and reconnects by itself if needed. Even after reloading you get your seat back.

In live games against humans with a running clock, your opponent sees “left the page” while you’re away. At the end of the game both see, neutrally, how often and how long someone was away. None of this is stored.

The computer plays at 10 levels, from 1 (“Newcomer”, often plays anything) to 10 (“Master”). You choose the level before the game; until your first move you can still change it, with a click or the keys 1 to 0. After that it holds for the whole game – and exactly this level counts for your progress. For a different level, start a new game.

Only against the computer there are two kinds of help:

• Hint (T): the best move is marked on the board.
• Undo (U): takes back your last move together with the computer’s reply – even after the game has ended.

Against humans there is neither hint nor take-back. Some badges only count if you win without these helps. There are no draw offers against the computer.