Play Chess960 against the computer

Free, no account. Roll one of the 960 starting positions or paste a FEN, pick a difficulty, and play. Or just move a piece to begin.

Why play Chess960?

In standard chess the first fifteen moves are usually somebody else's work. You play a line because it is known to be good, your opponent answers because they know it too, and the game only really starts once one of you runs out of preparation.

Chess960 removes that. The back rank is shuffled, so neither of you has seen the position and neither of you has anything prepared. You are working the game out from move one instead of recalling it.

Three things follow. There is nothing to memorise, so the hours other players spend on opening files go into calculation instead. The preparation gap closes, which is why a club player meets a stronger opponent on better terms here than in a theoretical line. And no two games open the same way, so the position in front of you is genuinely new every time.

It is the same chess. Same pieces, same rules, same checkmate. What it takes away is the memory, and what is left is the part most people wanted to be good at. Is Chess960 better? and how it compares to standard chess.

What is Chess960?

Chess960, also called Fischer Random, is ordinary chess with the back rank shuffled into one of 960 legal starting positions. Same pieces, same moves, same checkmate. Only two things change:

• Where the pieces start. Bishops on opposite colours, king between the rooks, Black mirroring White. Those three rules leave exactly 960 arrangements.
• How castling is described. The king and rook still finish on g1/f1 or c1/d1. Only their starting squares differ.

There is no opening theory to memorise, so the game is decided by calculation from move one. Full rules and castling →

How strong is the computer?

Five levels, from a beginner that overlooks things to an opponent that punishes them. The engine searches with alpha-beta and a quiescence search, so it will not hang a piece at the end of a line.

• 1 and 2 for learning the variant, or a fast game
• 3 for club strength. It replies in well under a second
• 4 and 5 take longer and forgive less

It plays Chess960 natively, including castling from unfamiliar squares, rather than treating it as standard chess with an odd first rank.

How does castling work here?

Castle by moving your king onto your own rook. That is the Chess960 convention, and it removes the ambiguity of "kingside" when the rooks can start anywhere.

The king and rook always land on the standard squares, which produces cases that look wrong and are legal: the king may not move at all, the rook may not move at all, and the king may travel left to castle short.

Where to go next

• Puzzle trainer. Engine-verified tactics from real Chess960 games, rated 1200 to 2400.
• Position generator. Any of the 960, with its FEN and castling squares.
• Books. A thousand puzzles each, free to read with Kindle Unlimited.