Secret Pawn Chess
Full rules
Choose two of your original pawns before play. They keep their pawn moves and can also move or capture one square in any direction.
Start from the standard chess position. All ordinary chess rules apply, with the changes below.
Setup and movement
- Each player chooses exactly two of their eight starting pawns and seals the choice. You cannot change your choices during the game. The power stays with each chosen pawn even if it changes files. White moves first once both players have sealed.
- You see neckties on your secret pawns. Your opponent sees those neckties only when the pawns are revealed. A revealed pawn keeps its extra moves until capture or promotion.
- A secret pawn can move or capture one square in any direction, as well as make ordinary pawn moves. It can move sideways or backward, capture straight ahead, or move diagonally to an empty square.
- A secret pawn may enter an attacked square, but no move may leave your king in check. Its attacks count for king safety and castling even while it is hidden.
- A pawn can advance two squares only on its first move, with both squares clear. Any earlier move, including a sideways or backward step, uses up that right. Returning to its starting square does not restore it.
- En passant is possible only on the next move after an ordinary two-square pawn advance. A secret pawn’s extra step does not allow an en passant reply.
When a secret pawn is revealed
- An extra move: it makes a legal move or capture that an ordinary pawn could not make in that position.
- Check with its extra power: after a legal move, it attacks the enemy king in a direction unavailable to an ordinary pawn.
- An otherwise safe king move: after a legal move, its hidden extra power prevents the enemy king from moving to an empty adjacent square that would otherwise be safe. If several hidden pawns prevent that same king move, all of them reveal.
- Capture: it is captured, including by en passant.
The empty-square rule applies to both kings after every legal move. The secret pawn need not move. To decide whether a square would otherwise be safe, consider the king on that square, with its old square empty. Ignore only the extra attacks of still-hidden pawns. Ordinary attacks, revealed pawn powers and attacks exposed by the king’s move still count. An occupied square does not trigger this rule, even if the king could capture its occupant.
An illegal move reveals no pawns. If a hidden pawn’s extra power is the only obstacle to a king move, the game may tell you that a secret pawn attacks the destination. It will not identify the pawn or say how many there are. The board and turn stay unchanged. Your clock keeps running, with no extra time added. Illegal castling gets the usual illegal-move message.
Examples
Neckties identify the chosen pawns in these examples, including those still hidden from an opponent. A faint piece marks the square just vacated; an outline marks the square being discussed.
1
A sideways move reveals the pawn
The pawn moves sideways to e4 and reveals. It keeps its power. An ordinary d4 → d5 move in this position would leave it hidden.
2
A forward move gives check and reveals the pawn
The pawn advances to d5, then gives check straight ahead on d6 and reveals. Before the move, the rook already attacked d5, so that square did not reveal the pawn early. An ordinary diagonal pawn check does not reveal it by itself.
3
A rook move reveals a pawn
The rook leaves d4 empty beside the king on e3. Only the hidden pawn’s sideways attack from c4 makes d4 unsafe, so the pawn reveals. The knight occupies d3; d5 is not beside the king.
4
A bishop’s shared threat keeps the pawn hidden
The bishop on c3 and the secret pawn on c4 both attack d4. d4 is already unsafe for the king because of the bishop on c3, so the pawn stays hidden. The knight occupies d3; d5 is not beside the king.
5
Two pawns reveal together
The rook leaves d4 empty. Both hidden pawns attack d4 with their extra power, and no ordinary attack makes it unsafe for the king on e3. Both pawns reveal together. The knight on d3 blocks the other adjacent square they attack.
6
Capture reveals the captured pawn
White’s ordinary pawn captures on d5. The black pawn is revealed and keeps its necktie beside the board. White’s pawn gains no extra power.
Neckties, capture and promotion
A necktie marks a pawn chosen at the start, even after its secret is known. Neckties stay on revealed and captured pawns. Capturing a secret pawn does not give the capturing piece any extra power.
When a pawn reaches the far rank, promote it to a queen, rook, bishop or knight as part of that move. It loses its necktie and secret-pawn power, and moves only as its new piece. The game record still identifies it as one of your original choices.
For example, a secret white pawn can move from e7 to empty f8 and promote to a knight. That diagonal move reveals it; the new knight has only knight moves. An ordinary e7 → e8 promotion does not reveal a hidden pawn just because it promotes.
Results and draws
Checkmate and stalemate take all secret-pawn powers into account. You can also resign or agree to a draw.
You can claim threefold repetition or the fifty-move rule when the position qualifies. You may also claim by declaring a legal move that would qualify, without playing it. Fivefold repetition and the seventy-five-move rule end the game automatically. Checkmate takes priority if the mating move also reaches the automatic move limit.
Every pawn move, including an extra step, and every capture resets the fifty-move and seventy-five-move counts. Moves by a promoted piece are no longer pawn moves. For repetition, identical piece placement is not enough: secret-pawn choices, revealed powers and move rights also matter.
The game automatically draws these positions: king against king; kings with just one bishop or knight between them; or kings and only bishops, all on the same square color. Other dead positions are not detected automatically.
If your clock runs out, you lose unless your opponent lacks possible mating material, in which case the game is drawn. A bare king cannot mate. A lone knight or bishops on one square color need opposing material to help block the king. A pawn, rook, queen, two knights, bishop and knight, or bishops on both colors count as possible mating material against a bare king. The question is whether mate is possible, not whether it can be forced.
When the game ends, both players’ original secret pawns are shown, including captured and promoted pawns. In a replay, you can choose to see only what you knew at each move or reveal both players’ choices from the start.
Move notation
The move list uses x for capture, =Q, =R, =B or =N for promotion, + for check and # for mate. Two asterisks mark a reveal: Rd5 **c4 means the rook moved to d5 and revealed a secret pawn on c4. Several revealed squares are separated by commas.
A secret pawn revealed by capture gets ** without a square, as in cxd5 **. This also applies to en passant. If the same move reveals other pawns still on the board, their squares follow a second pair of asterisks.
Starting and returning to a game
Quick play pairs you with another waiting player for a 5+3 game. To play someone you know, choose Invite a friend and share the invitation link. Choose 5+3 or no clock for an invitation.
In 5+3, each player starts with five minutes and gains three seconds after each legal move. Choosing your secret pawns does not use your game time.
A no-clock game lets you return between moves. Keep the game link and use the same browser. You can have one active game at a time. There are no turn notifications, so arrange turns with your opponent.
No account is needed. Your access is stored in this browser’s site data. Clearing that data loses access to your games; a saved link alone will not restore it or let you switch browsers.