Two players (one is Human, the other is Alien) face each other and seek to destroy their opponent by dealing 3 damage to their planet. The planets are separated by 18 spaces. The Human has 5 ships available, spawning from the Mothership (placed adjacent to Earth at the beginning of the game). The Alien has 5 flying saucers at his/her disposal, spawning from the Vortex (placed adjacent to the alien planet at he beginning). A die roll determines the first player. Then each turn, the active player rolls 2 six-sided dice. The dice values can be used to move two space vehicles he/she owns (ships or flying saucers) or only one (by combining the two values). Space vehicles can only go forward, not backward. A die showing "1" can be used to move the Mothership/Vortex 1 space. A space can only hold one token: A space vehicle landing on an enemy vehicle captures it (it is removed from the board and return in the owner's Reserve). A space vehicle supposed to land on the Mothership/Vortex lands one space farther. A space vehicle landing on the enemy's planet (or farther) deals one damage and return in the Reserve. At each damage dealt, the attacked player wins a special power of his choosing (among the special powers still available): re-roll one die each turn "+1" to each die each turn you choose to play with only one die, all the opponent's vehicle you jump over are captured your tokens can move backward your vehicles can stack up to two on the same space, protecting them from being captured. These special powers are permanent power-ups. —description from the publisher