A special unit is a unit that does not fall into any of the other unit classes and cannot be produced or obtained in the same manner as other units. There are two special units in Civilization Revolution, both of which provide military advantages: the Great General (which is awarded through exceptional performance in battle and boosts the attack and defense of the unit in its tile) and the ICBM (which is awarded for building the Manhattan Project and can be used to launch a single devastating attack).