OFFICIAL RULES · CURRENT VERSION
How to play Exoplanet Chess
QUICK INTRODUCTION
Two kings begin. You create the opening.
Every other piece begins in reserve. On each turn, decide whether to deploy a new piece or move a piece already on the board. Think ahead, build your position and checkmate the opposing king.
For experienced chess players
- Begin with only the two kings on their traditional starting squares.
- Think and plan your position.
- Choose a piece from your reserve.
- Either deploy that piece on an empty square in your half of the board, or move a piece already in play.
- Use strategy, timing and position to checkmate the opposing king.
For new players
- PawnMoves exactly one square forward, including its first move. Captures one square diagonally forward.
- RookMoves and captures in straight lines—forward, backward or sideways.
- KnightMoves and captures in an L-shape: two squares in one direction, then one square to the side.
- BishopMoves and captures diagonally.
- QueenMoves and captures in any straight or diagonal direction.
- KingMoves and captures one square in any direction, but may never move into check.
Your goal: Checkmate the opposing king—place it under attack with no legal escape.
Watch the moves
Click a piece below to watch every direction, one after another. The demonstration repeats until you press Pause.
Deploy
1 of 2: White deploys in ranks 1–4
Choose one reserve piece and place it on an empty square in your own half. Deployment uses your turn.
Reserve → c3
The centre line limits deployment only. Deployed pieces can move across it.
Complete rules
- Objective: Checkmate the opposing king.
- Starting position: The White king begins on e1 and the Black king begins on e8. Every other standard chess piece begins off the board in reserve.
- One action per turn: Move one piece already on the board, or deploy one unused reserve piece. A deployment uses the entire turn.
- Deployment zone: All reserve pieces, including pawns, deploy only on an empty square in their player’s half—White ranks 1–4 and Black ranks 5–8.
- Bishop deployment: Your two bishops may be deployed on the same row or on different rows, and on squares of the same colour or different colours. Each bishop uses a separate turn and an empty square within your half. After deployment, each bishop moves diagonally and stays on the colour of square where it was placed.
- Pawn movement: A pawn moves exactly one square forward to an empty square, from any row and including its first move. There is no two-square move. White pawns move towards rank 8; Black pawns move towards rank 1. Pawns capture one square diagonally forward and promote to a queen upon reaching the farthest rank.
- Other movement: After deployment, all other pieces move, attack and capture according to traditional chess rules. All pieces, including pawns, may cross the centre line when moving; the half-board limit applies only to deployment.
- King safety: A move or deployment cannot leave your own king in check. A legal deployment may give check or defend against check.
- Special rules: Castling and pawn en passant are not allowed. Captured pieces are permanently removed and do not return to reserve.
For an over-the-board game, determine the starting player by a coin toss. In the online game, follow the assigned colour and the on-screen turn indicator.