Pawn promotions are allowed in either direction the pawn can move. Q-Queen, K-King, R-Rook, B-Bishop, N-Knight, P--Pawn
No en passant.
Pieces move normally, except pawns, which move in an extra direction and capture in an extra direction.
Pawns can jump on their first double move.
You can have multiple kings.
You lose when all your kings die.
When you lose, the remaining players keep playing, but your pieces stay on the board. They can no longer be moved, but they can still be captured and when captured the same rules as a king capture apply.
If you capture an enemy king, that king becomes your king.
After capturing an enemy king, you get an extra turn. In this turn, you must either move your new king or the piece you used to capture it but you are not able to capture additional pieces with this turn.