The Board

Void Chess is played on a 9x9 board (81 squares) instead of the standard 8x8. This extra column gives room for the new Minister piece.

Starting Position

Minister (new piece)

Starting Position

Each side starts with 9 pawns and the following back rank:

Standard Piece Movement

All standard chess pieces move exactly as in normal chess:

• King — 1 square in any direction
• Queen — Any number of squares in any direction
• Rook — Any number of squares horizontally or vertically
• Bishop — Any number of squares diagonally
• Knight — L-shaped (2+1), can jump over pieces
• Pawn — 1 square forward (2 from start), captures diagonally

Castling, en passant, and pawn promotion all work exactly like standard chess. Pawns can also promote to a Minister!

How the Minister Moves

The Minister moves in two steps:

1. Step 1: Move 1 square in any direction — to an empty square or to capture.
2. Step 2 (optional): If Step 1 landed on an empty square, continue 1 more square in any direction — it can change direction!

How Blocking Works

The Minister needs empty adjacent squares to move through. If completely surrounded by friendly pieces, it has no legal moves at all.

But even a single opening creates movement possibilities:

Minister's Healing Power

• When the Minister moves onto an unstable tile, it becomes a normal tile
• When the Minister moves onto a void tile, it becomes a normal tile
• The Minister is the only piece that can move onto void tiles
• The Minister is immune to void death

Before the Capture

White's Rook is about to capture Black's Pawn.

Step 1: Capture Creates Unstable Tile

When a piece captures another piece, the tile where the capture happened becomes unstable (glows red). The capturing piece is safe this turn.

Step 2: Move Away or Get Destroyed

Void Tile Rules

• Void tiles are impassable — no piece can move through or land on them (except the Minister)
• Voids are permanent — they never go away (unless healed by the Minister)
• Sliding pieces (Rook, Bishop, Queen) are blocked by void tiles
• Knights cannot jump to void tiles
• The board shrinks as voids accumulate

King on Unstable Tile

If your King is on an unstable tile, you must move the King on your next turn. If the King has no legal moves, it is destroyed and you lose the game.

Win Conditions

• Checkmate — opponent's King has no legal moves while in check
• King lost to void — opponent's King is destroyed on an unstable tile
• King trapped by void — opponent's King is not in check, but every move would expose it to the void janitor. This is a loss, not a draw

Draw Conditions

• Stalemate — no legal moves, not in check, and not caused by void trapping
• Threefold repetition — same position occurs 3 times
• 30-move rule — 30 moves with no pawn move or capture (reduced from 50 because voids shrink the board)
• Insufficient material — only Kings remain
• Void Fortress — a King is completely enclosed by voids with no way in

Pawn Promotion

When a pawn reaches the last rank, it can promote to:

Article 1 — The Board and Starting Position

1.1. Void Chess is played on a square board of 81 squares arranged in a 9-column by 9-row grid. Columns are labelled a through i. Rows are numbered 1 through 9 from White's side.

1.2. Each player begins with 16 pieces: 1 King, 1 Queen, 1 Minister, 2 Rooks, 2 Knights, 2 Bishops, and 9 Pawns.

1.3. White's back rank (row 1), from a1 to i1: Rook, Knight, Bishop, Queen, King, Bishop, Minister, Knight, Rook. White's 9 Pawns occupy row 2.

1.4. Black's back rank (row 9) mirrors White's arrangement. Black's 9 Pawns occupy row 8.

1.5. At the start, every square is in the Normal state. There are no unstable or void tiles.

1.6. White moves first. Players alternate turns. A player must make exactly one move per turn.

Article 2 — Tile States

2.1. Each square exists in one of three states: Normal, Unstable, or Void.

2.2. Normal tiles function as ordinary chess squares.

2.3. Unstable tiles are created when a capture occurs. Any piece remaining on an unstable tile at the end of that piece's team's turn is destroyed by the Void Janitor, except the Minister.

2.4. Void tiles are permanent gaps in the board. No piece may move to, through, or occupy a void tile, except the Minister.

2.5. When a piece leaves an unstable tile, that tile immediately becomes void.

Article 3 — Movement of Standard Pieces

All standard pieces move according to orthodox chess rules, with the constraint that void tiles are impassable.

3.1. King — 1 square in any direction. May not move to a void tile or into check.

3.2. Queen — Any number of squares horizontally, vertically, or diagonally. Blocked by void tiles and occupied squares.

3.3. Rook — Any number of squares horizontally or vertically. Blocked by void tiles and occupied squares.

3.4. Bishop — Any number of squares diagonally. Blocked by void tiles and occupied squares.

3.5. Knight — L-shape (2+1). Jumps over pieces and void tiles, but may not land on a void tile or a friendly piece.

3.6. Pawn — 1 square forward (2 from starting row if both squares are empty and not void). Captures 1 square diagonally forward. May not move onto void tiles.

Article 4 — The Minister

4.1. Starts on g1 (White) and g9 (Black).

4.2. Movement — Two-step sequence in a single turn:

• Step 1: Move 1 square in any direction (horizontally, vertically, or diagonally). The destination must be empty or occupied by an enemy piece (a capture). The destination may be a void tile or an unstable tile.
• Step 2 (conditional): If and only if Step 1 landed on an empty square (no capture), the Minister may move 1 more square in any direction. It may change direction between Step 1 and Step 2. The Step 2 destination may not be the Minister's original square. Step 2 is optional.

4.3. If the Minister captures on Step 1, the move ends immediately. No Step 2.

4.4. On Step 2, the Minister may land on an empty square or capture an enemy piece.

4.5. On an open board with no obstructions, the Minister can reach up to 24 distinct squares (all squares within a 5x5 area centred on the Minister, excluding its own square).

4.6. Healing. When the Minister moves onto an unstable tile or a void tile, that tile is immediately restored to Normal state. The Minister is the only piece that may move onto void tiles.

4.7. Void Immunity. The Minister is immune to the Void Janitor and is never destroyed by remaining on an unstable tile.

4.8. Blocking. The Minister requires at least one adjacent square (Step 1 destination) to be either empty or occupied by an enemy piece. If all 8 adjacent squares are occupied by friendly pieces, the Minister has no legal moves.

Article 5 — Captures and Unstable Tiles

5.1. When any piece captures an opponent's piece, the capture square becomes unstable. If the square was already unstable from a previous capture, it remains unstable. If the square is void, it remains void (only possible with the Minister).

5.2. If the Minister makes the capture, the tile is healed to Normal instead.

5.3. En passant captures create an unstable tile on the square where the capturing pawn lands.

5.4. The capturing piece is safe on the unstable tile for that turn. See Article 6 for what happens next.

Article 6 — The Void Janitor

6.1. Automatic process that runs at the end of every turn.

6.2. For every unstable tile on the board:

• Safe square: The square the moving piece just arrived on is exempt.
• Friendly pieces on unstable tiles (belonging to the team that just moved) are destroyed and the tile becomes void. The Minister is exempt.
• Opponent's pieces are not affected by the janitor.

6.3. If the King is destroyed by the Void Janitor, that player loses.

Article 6A — Life Cycle of an Unstable Tile

6A.1. Creation. A capture occurs. The square becomes unstable. The capturing piece is safe this turn.

6A.2. Escaping. If the piece later moves away from the unstable tile, the tile immediately becomes void. The piece survives.

6A.3. Destruction. If the player moves a different piece instead, the Void Janitor destroys the piece still sitting on the unstable tile. The tile becomes void.

6A.4. Opponent's turn. During the opponent's turn, the capturing piece is not affected — the janitor only destroys pieces of the team that just moved. The piece survives through the opponent's turn.

6A.5. Recaptures. If the opponent recaptures on the same tile, it stays unstable. The new piece is safe this turn. The cycle restarts. As long as captures keep happening on the same square, it stays unstable and never becomes void.

6A.6. Summary. Capture → Unstable → Safe this turn → Escape (piece lives, tile becomes void) or Stay (piece dies, tile becomes void). Recaptures reset the cycle.

Article 6B — Example: Escape and Destruction

White's Rook captures Black's Knight on e5.

Option A: White moves the Rook away from e5. The Rook survives. Tile e5 becomes Void.

Option B: White moves a different piece. The Rook stays on unstable e5. The Void Janitor destroys the Rook. Tile e5 becomes Void.

White must weigh saving the Rook against making a different move. Sometimes sacrificing a piece is the right choice.

Article 6C — Example: Recaptures

Repeated captures on the same square keep it unstable.

Three captures on e5 and it stayed unstable the whole time. The void was only created when the last piece finally left.

Article 7 — Special King Rules

7.1. Check. A King is in check when attacked by one or more opponent pieces. A player whose King is in check must resolve the check on that turn by moving the King, blocking the attack, or capturing the attacking piece.

7.2. King on an unstable tile. If a King is on an unstable tile at the start of that player's turn, the player must move the King. No other piece may be moved.

7.3. If the King is on an unstable tile and has no legal escape, it is destroyed by the Void Janitor at the end of the turn. That player loses.

7.4. The King may not move onto a void tile.

Article 8 — Castling, En Passant, Promotion

8.1. Castling. King and Rook must not have moved. All squares between them must be empty and not void. King must not be in check, pass through check, or land in check. King moves 2 squares toward the Rook; the Rook moves to the square the King crossed.

8.2. En passant. Standard chess rules apply. Must be exercised on the immediately following turn.

8.3. Promotion. A Pawn reaching the opponent's back rank must promote to Queen, Rook, Bishop, Knight, or Minister.

Article 9 — End of the Game

Win conditions:

• 9.1. Checkmate. King is in check with no legal move to escape. That player loses.
• 9.2. King destroyed by void. King is destroyed by the Void Janitor. That player loses.
• 9.3. King trapped by void. King is not in check, but every available move would expose the King to destruction by the Void Janitor. That player loses. This is distinct from stalemate.

Draw conditions:

• 9.4. Stalemate. Player has no legal move and is not in check (and not void-trapped). Draw.
• 9.5. Threefold repetition. Same position occurs 3 times with the same player to move, same castling rights, same en passant, and same tile states. Draw.
• 9.6. Thirty-move rule. 30 full moves by both sides with no pawn move or capture. Draw.
• 9.7. Insufficient material. Only Kings remain on the board. Draw.
• 9.8. Void Fortress. A King is enclosed by voids, no opponent piece can reach it, no Minister exists on the board, and no Pawn has a void-free path to promotion. Immediate draw.

Article 10 — Move Legality

10.1. A move is legal only if, after execution and Void Janitor simulation, the moving player's King is not in check and has not been destroyed.

10.2. Void tiles block sliding pieces and prevent Knight landings in all attack calculations.

Article 11 — Notation

11.1. Files a–i, ranks 1–9. Piece letters: K, Q, R, B, N, M. Pawns omit the letter.

11.2. Captures: x. Check: +. Checkmate: #. Castling: O-O / O-O-O. Promotion: =M (e.g. e9=M).