"Mystic Chess" is a chess variant using an orthodox chess board with unorthodox rules.
The game differs from the standard chess game in the following rules:
- The starting position only includes the White and Black kings, at their standard positions (on e1 and e8 respectively). The remaining chess pieces are placed beside the board for further use.
- Each player starts with 20 coins, to be placed in front of him, which are used to buy pawns and upgrade pieces. In case no physical coins/tokens are available, a sheet op paper can be used to monitor the number of coins remaining for each player, which should be visible during the full duration of the game.
Starting position, with 4 stacks of 5 coins on each side
- At his turn, a mystic chess player has the choice between 3 different actions:
- Play a standard chess move
- Buy one pawn with one coin. The coin should be removed from his personal stock and put aside. The pawn can be dropped in any unoccupied square between ranks 2 and 4 for White, and between ranks 5 and 7 for Black.
- Upgrade one piece according to the standard evaluation used in chess: a Queen is worth 9 points, a rook 5 points, a bishop or a knight 3 points and a pawn 1 point. The upgrade should be done progressively, which means a pawn can only be upgraded to a bishop or knight (by paying 2 coins, as it is the difference in evaluation between the 2 pieces). Then the bishop or knight can be upgraded to a rook by paying 2 extra coins, which in the next turn can be converted into a Queen by paying 4 extra coins.
Action 2 should be performed at least 3 times before action 3 can be performed. This allows building a basic pawn structure before being attacked by the opponent's pieces. So in practice the players have to buy at least 3 pawns before upgrading them to higher pieces. After these 3 first pawns are bought, any number of pieces can be upgraded, as long as enough coins are available to pay the upgrade. There can however not be more pieces of one type than in a standard chess set. For instance, White or Black are not allowed to upgrade 3 pawns to have 3 bishops at the same time on the board. It is allowed to have two light-squared or two dark-squared bishops.
A pawn reaching the 8th rank can be promoted as usual to a piece (bishop, knight, rook or queen), but only as long as it is still available (so not to a queen if a queen is already on the board, for instance if bought earlier with coins). Pieces than have been captured or upgraded to a higher piece are going back to the stock of pieces available for upgrade with coins or promotion of pawns on the last rank.
As in standard chess, the winner is the player who can checkmate his opponent.
