How does Chess960 differ from ordinary chess?
Chess960: the starting position
Choose a number below to explore a starting arrangement. Number 518 gives the familiar classical setup; the pieces still move in their usual ways. This numbering is a way to identify positions, not a requirement of Guidelines II.
- White’s pawns remain on rank 2; the other pieces occupy rank 1.
- Bishops start on opposite-coloured squares.
- The King starts between the two Rooks.
- Black’s pieces stand opposite White’s, with pawns on rank 7.
Guidelines II.1–II.2 allow a computer or physical randomisation such as dice or cards to generate the arrangement. Ordinary piece movement and the objective of checkmate remain.
Explore Chess960 starting positions
Why there are 960 starting positions
Count the arrangements permitted by the starting-position constraints: four choices for the bishop on light squares, four for the bishop on dark squares, six remaining places for the queen, and ten ways to place the two identical knights in the five remaining squares. The final three squares must contain rook–king–rook, in that order. Thus 4 × 4 × 6 × 10 = 960.
This is a count derived from Guidelines II.2, not an extra rule about how a tournament must draw a position. The explorer’s 0–959 numbering identifies arrangements; number 518 gives the familiar classical setup. Black uses the matching arrangement opposite White.
Chess960 castling: fixed destinations
Scroll the table sideways to compare all columns.
| Side | White finishes | Black finishes |
|---|---|---|
| g-side, O-O | King g1, Rook f1 | King g8, Rook f8 |
| c-side, O-O-O | King c1, Rook d1 | King c8, Rook d8 |
The example begins with a King on b1 and Rooks on a1/h1. Advance the first board to g-side castling; the second shows c-side castling. In each example, follow the King and Rook to their final squares.
Depending on the start, castling can move both pieces, swap them, move only the King, or move only the Rook. The King and participating Rook must retain the relevant rights. The King may not castle out of, through or into check. All squares on both travel paths, including destinations, must be empty except for that King and Rook. Sometimes one of the two is already on its final square. Guidelines II.3.
Announcing the intention to castle is recommended to avoid misunderstanding on a physical board. Do not assume the King must always travel two squares in Chess960.
Check destinations first, then trace both paths
Scroll the table sideways to compare all columns.
| Position before a kingside castle | What changes? | Final squares |
|---|---|---|
| King g1, rook h1 | Only the rook moves | King g1, rook f1 |
| King e1, rook f1 | Only the king moves | King g1, rook f1 |
| King f1, rook g1 | King and rook exchange squares | King g1, rook f1 |
These examples describe the movement pattern, assuming the castling right and all path and king-safety conditions are satisfied. They are not permission to castle in every position containing those two pieces.
On a physical board, announce the intention if needed to avoid confusion. Guidelines II.3.2.5 recommends lifting the king outside the playing surface near its final square, placing the rook, then placing the king. For judging legality, examine the king’s route and the rook’s route separately; do not simply count two king steps as in ordinary chess.
FAQ
Can the king stay where it is during castling?
Yes. If the king already occupies its castling destination, only the rook may need to move. The castling right, clear-path requirements and king-safety conditions still apply; a stationary king does not make castling automatic.
Can Black choose a different starting arrangement?
No. Black’s pieces are placed opposite White’s under Guidelines II.2.3. Both players start from the same arrangement viewed from their own side.
Related rules
- Chess rules for beginners: moves and touch-move
- Castling, en passant and promotion explained
- Tournament chess: players, arbiters and accessibility
Playing with a visually impaired opponent
See the practical guide to adapted boards, move announcements and assistants.
Sources and scope
FIDE Laws of Chess · 2023 · Guidelines II.1–II.3.
Effective 1 January 2023. These guides explain over-the-board play. The official text and any event regulations permitted by it govern competition; teaching positions are not tournament records.