Rules / Shadow King
Shadow King chess: find the hidden True King
In Shadow King, the piece that decides the game is hidden. At the start, one piece on each side is secretly chosen as the True King. Capture your opponent's True King and you win at once, no matter what else is on the board. It's a game of incomplete information played on a chessboard.
The rules
- Each side gets one True King, chosen at random from its eight non-pawn pieces: King, Queen, two Rooks, two Bishops and two Knights.
- Your own True King is marked for you. You can't see the enemy's until the game ends.
- There's no check and no checkmate. You may leave any piece attacked, including the piece called the King.
- Capturing a King that isn't the True King doesn't end the game.
- You can castle whenever the King and Rook haven't moved, no matter which squares are attacked.
- Pawns promote as usual, but a promoted piece is never the True King, since the choice is made before the first move.
The odds, and how they move
At the start, each candidate has a 1 in 8 chance, or 12.5%. Each non-pawn piece you capture without ending the game removes one candidate, so the odds on the rest rise:
| Candidates captured | Chance for each one left |
|---|---|
| 0 | 1 in 8 (12.5%) |
| 2 | 1 in 6 (16.7%) |
| 4 | 1 in 4 (25%) |
| 6 | 1 in 2 (50%) |
Capturing pawns doesn't change these numbers, because a pawn is never a candidate. That makes the value of pieces different from normal chess. A knight worth three points in the usual count is also a 1 in 8 chance to win outright. A quick knight trade may be better for you than winning two pawns, as long as your own True King stays safe.
These are the starting odds, before you read your opponent's behavior. A real player gives away more information than the table can show.
Reading your opponent
Watch which pieces your opponent protects and which they leave hanging. A bishop that keeps running from a pawn's attack when the trade would be fair is suspicious. A queen left where it can be taken for free is probably not the True King, unless your opponent is bluffing. Pay attention to moves that make no sense for the position, because they're often about safety.
Hiding your own True King
Your opponent is doing the same reading, so treat your True King like every other piece. Three simple ideas help:
- Defend several pieces in the same way. If only one piece is always guarded, you've told them which one it is.
- Move it early if it's natural. A knight or bishop that develops normally looks ordinary. One that never moves can start to stand out.
- Protect a decoy now and then. Spending a move to rescue an unimportant piece costs a tempo, but it can buy a lot of doubt.
If your True King happens to be the King, you can castle it to safety just as you would in a normal game, and your opponent has no way of knowing that's why you did it.
Reading the screen
Your own True King carries a marker. The enemy's is hidden until the result screen and the replay, where both are revealed. Taking an ordinary King shows that the game goes on, which can be quite a surprise the first time.
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