Pawns

Setup pawns on opposite sides one row out (in normal pawn position). Play chess as you normally would with pawns having their normal rules including en passant. When a pawn reaches the other side they may become a piece of the controlling player's choice. Read below if you're unsure of the rules.

Pawns on their first move (moving from starting position) may advance two squares forward towards the other side. Other than that pawns may move one square forward when doing a regular move and one square diagonally forward when taking a piece.

Standard capture. If a pawn has an opposing team's pawn diagonally one square forward of it, it can move to that square and remove the other pawn.

En passant If a player has their pawn three squares forward and their opponent moves a pawn two squares forward to be next to the player's pawn, the player may move their pawn diagonally forward and behind the opponent's pawn, removing it from the board as if the opponent had only moved their pawn forward one space. This may only be done the turn after the opponent moves their pawn two squares forward.