Missiles are infrastructure and improvement artillery units that destroy more than 300 infrastructure (if available) and 1 improvement (of any kind, except for power plants). The city and type of improvement to be destroyed can be chosen by the attacker.
Nations may have an unlimited amount of missiles, but can only build one missile per day. They do not require any resources munitions or gasoline to use.
Missiles can be stopped by the Iron Dome project, which has a 50% chance of stopping a missile.