White Knights attack Black Warriors. White Warriors attack Black Knights. Black Knights attack White Knights. Black Warriors attack White Warriors.
A piece is attacked if an opposing piece eligible to attack it is a Knight's move away. For instance, a White Knight on g1 is attacked by a Black Knight on h3.
Captures are never made. A piece can move only to an empty square. The game is over when exactly one player has a piece or pieces under attack. In that case the player with a piece or pieces under attack loses. It is illegal for a player to make a move which leaves one or more of his pieces under attack unless his opponent also is left with one or more pieces under attack. If the game is not over but the player to move has no legal moves, a highly unlikely scenario, the game is a draw.
The starting position: White Warriors on c1 and d1. Black Warriors on c8 and d8. White Knights on e1 and f1. Black Knights on e8 and f8. White moves first.