This not-very-simple game comes in several forms, all based around this board:

Emperor Rules:

Moves:

Standard chess. Pawns can move up to two spaces forward on their first move and one square thereafter; taking can only be done by moving diagonally. Knight moves are L-shaped. Castles can move in straight lines. Bishops move diagonally. The Queen can move horizontally, diagonally and vertically. The King can move one square per move horizontally, diagonally or vertically.

Taking pieces:

If a piece is taken it is removed from the board.

Players:

Four - one per position. Play starts at position 1, then 3, then 2 and finally 4.

Winning:

The winner is the last player left standing. A player loses when their King is taken.

Tehran Rules:

Moves:

Positions 1 & 2: Standard chess. Pawns can move up to two spaces forward on their first move and one square thereafter; taking can only be done by moving diagonally. Knight moves are L-shaped. Castles can move in straight lines. Bishops move diagonally. The Queen can move horizontally, diagonally and vertically. The King can move one square per move horizontally, diagonally or vertically.

Positions 3 & 4: Pawns can move forwards one square, either straight ahead or diagonally. Knights can move two squares in a straight line (horizontally or vertically) or in L-shapes. Castles can move in straight lines. Bishops can move to any square within a 5x5 square (centring on the bishop). Queens can do the same within a 9x9 square. Kings can move two squares per move horizontally, diagonally and vertically. One King out of the two on positions 3&4 can be hidden from other players by leaving its space blank at the beginning.

Taking pieces:

Positions 1&2: If a piece is taken it must return to its starting position.

Positions 3&4: If a piece is taken it remains where it is but cannot move for 4 turns.

Players:

Two or four. Two players should handle positions 1&2 and positions 3&4 respectively. Four players should handle each side individually. Play starts at position 1, then 3, then 2 and finally 4.

Winning:

The winner is the last player left standing. A player loses when their king is taken, if all pieces other than their king are taken or if they suggest that a draw should be declared.

Cold Rules:

Moves:

Pawns can move up to two spaces forward on their first move and one square thereafter; taking can only be done by moving diagonally. Knight moves are L-shaped. Castles can move in straight lines. Bishops cannot leave their half of the board (based on a line drawn from 3c to 10j). The Queen can move to any space on the board but the fact that the Queen is being moved must be announced one turn in advance (the other side can retaliate during this turn without making this announcement). The King can move one square per move horizontally, diagonally or vertically.

Taking pieces:

If a piece is taken it is removed from the board.

Players:

Any number other than 1. Players divide themselves into two roughly equal teams. Team A controls positions 1&2 and Team B controls positions 3&4. The team should agree on each move before making it. Players may move between teams if they disagree with the course the team is taking.

Winning:

The winning team is the one which did not lose. A team loses if both its Kings are taken or if it collapses into argument and personal abuse, with the consequence being that further play is impossible.