From back of the box:
Object of the game:
Ninja warriors attack the Fortress. The defenders inside the Fortress walls must prevent them from stealing the treasure.
Ninja is a simple game of movement and dice combat. One player is the attacker while the other player is the defender. Each player's ninja pieces show its movement, range, and attack properties. When two pieces battle, each player adds the attack number of their battling piece to the roll of two dice, with the highest total winning the battle. Eventually, the defender will either have prevented the attacker from stealing the treasure, or the attacker will make off with the treasure, winning the game. It is suggested that two rounds are played, with players switching roles and comparing the points that they gained when they played the attacker in order to determine a winner.