I had to figure there were times when the humble pawn grew frustrated
with his lowly position in the King's army.
Or maybe some have been the subject of mind-control experiments.
Or maybe they can be whipped into a holy-war frenzy by their leaders.
In any event, I felt the idea of the Berserker would make a player
think thrice before kicking another loyal foot soldier.
Pawns set up, move, capture and are captured as regular pawns (FIDE or as otherwise dictated by other variants in play), but have the ability to go Berserk, becoming crazed killing machines (Berserkers), heedless of their own safety.
A Berserker may move up to seven (7) squares in any direction or combination of directions, and must attack at the end of the move; that is, must end the move in a space occupied by an opposing piece.
A Berserker may not:
pass through/over occupied squares,
end a move in an unoccupied square,
end in a square occupied by a friendly piece, or
attack the opposing king.
(This last is unrealistic, but necessary for game balance.)
When the Berserker ends his move, the defending piece and the Berserker are removed from the board. A Berserker move is effective, but suicidal.
Pawns may Berserk in only two situations
A pawn may Berserk if it's king is in check. The Berserk attack must rescue the king / end the check.
Once during the game a player may declare a pawn has gone berserk. That declaration, the movement and attack of the berserk pawn constitute the player's turn. Only one pawn per game may voluntarily Berserk outside of a check situation, but any available pawn can be selected.