The second game in the "AvA" series that started with Army vs. Aliens. It is a stand alone 2 player game, but can be combined with the other games in the series for variety or for larger games.
Each player takes one of the factions and rolls all 9 dice. Then players alternate either attacks or using a special power. Dice that are used are put back into the dice cup. If a player cannot attack or use a power, they instead 'rally' and roll the dice cup (and reroll any or all of their dice still in play).
The two forces have different special powers.