How do drops work in Crazyhouse?

When you capture a piece it goes into your pocket. On any later turn, instead of moving a piece, you may drop a pocket piece onto any empty square. Pawns cannot be dropped on the first or last rank, and a promoted piece returns to the pocket as a pawn.

How does castling work in Chess960?

After castling the king and rook always end on the same squares as in standard chess (king on c or g, rook on d or f). All squares between the pieces and their destinations must be empty, the king may not pass through check, and neither piece may have moved. In this app you castle by tapping your king and then your rook.

Can I play Crazyhouse 960 against a computer?

Yes. The AI is Fairy-Stockfish running in your browser via WebAssembly, with selectable strength levels. Nothing is uploaded; the engine runs locally.

Crazyhouse 960 — Chess with Drops & Random Starts

Q: What is Crazyhouse 960?

Crazyhouse 960 combines two chess variants: Crazyhouse, where captured pieces can be dropped back onto the board as your own, and Chess960 (Fischer Random), where the back-rank pieces start in one of 960 randomized arrangements.

What is Crazyhouse 960?

Crazyhouse 960 is chess with two twists. From Crazyhouse it takes drops: every piece you capture goes into your pocket, and on a later turn you can place it back on the board as your own. From Chess960 (Fischer Random) it takes the random start: the back-rank pieces begin in one of 960 legal arrangements, so there are no memorised openings — you read the position from move one.

The game on this page is already running. You play White against a Fairy-Stockfish AI that runs inside your browser; nothing is uploaded.

How Crazyhouse drops work

Capture a piece and it appears in your pocket below the board (your opponent's pocket is above it). When it is your turn, tap a pocket piece: every empty square where it may legally be dropped lights up. Tap one to drop it. A drop can give check or checkmate just like a normal move.

Pawns cannot be dropped on the first or last rank.
A promoted piece that gets captured goes into the pocket as a pawn.
You may drop instead of moving, but never both in one turn.
Dropped pieces are ordinary pieces: they move, capture and can be captured again.

What is Chess960?

Chess960, also called Fischer Random chess, shuffles the pieces on the first rank under three rules: the bishops stand on opposite-coloured squares, the king stands somewhere between the two rooks, and Black's setup mirrors White's. That yields 960 possible starting positions (standard chess is number 518). Pawns start where they always do.

How castling works in Crazyhouse 960

Castling in Chess960 ends exactly like castling in standard chess: after kingside castling the king is on g1 and the rook on f1; after queenside castling the king is on c1 and the rook on d1 (c8/d8 and g8/f8 for Black). The pieces may start anywhere on the rank, so the king might move zero, one or several squares. The usual conditions apply: neither piece has moved, every square between each piece and its destination is empty (apart from the two castling pieces themselves), and the king is not in check and does not pass through or land on an attacked square.

In this app you castle by selecting your king and then tapping your own rook, which is the convention used by chess servers for Chess960. Crazyhouse adds no extra castling rules.

Crazyhouse vs standard chess

Material never leaves the game, so trades are not simplifications: every exchange arms both pockets. Attacks are faster and king safety matters far more, because a single dropped knight or pawn can create threats out of nothing. Endgames in the classical sense are rare — most games are decided by a mating attack while the board is still full. Combined with Chess960, the opening phase becomes pure calculation rather than preparation.

FAQ

Do I have to read instructions to play?

No. Pieces that can move glow softly, legal destinations are marked with dots, pocket pieces glow when they can be dropped and their legal squares light up when selected, and a king in check is highlighted in red.

Which view should I use?

Perspective shows a physical-looking board seen from White's side; Top is a flat diagram for maximum readability. Switch with the two icons in the top bar — the choice is remembered on this device.

The options button (the gold and walnut knights) opens the game settings: the piece set, the start position (random Chess960 or the standard setup) and drops (on for Crazyhouse, off for plain chess). The default is Crazyhouse from a random start; a change applies to the next game, or immediately if no move has been played yet.

How strong is the AI?

The engine is Fairy-Stockfish compiled to WebAssembly, the same engine used by major variant servers. Its strength is adjustable from beginner to full strength via the level selector.

Is this the same as Crazyhouse on chess servers?

Yes — the rules follow the standard Crazyhouse implementation used online (drops, pawn-drop restrictions, promoted pieces reverting to pawns), and the Chess960 start positions and castling follow FIDE's rules.