Many vehicles and structures in the game have armor to protect them from disaster and attack. The damage done by weapons and disasters may be either concussion damage or penetration damage; many weapons do both kinds of damage. Concussion damage, which results from the application of raw force, can be partially reduced by armor. Penetration damage, which results from the piercing of shrapnel or other projectiles, slices right through armor. Armor comes in three different levels: light, medium, and heavy.
Some weapons are “direct-fire” weapons. These weapons must have a clear line of sight in order to fire at their targets. The line of sight may be blocked by structures, walls, or certain terrain features, such as volcanoes and boulders. The Microwave, Laser, and Rail Gun turrets, as well as the Scorpion's weapon, are direct-fire weapons. All other weapons are “indirect-fire”; that is, they may ignore line of sight considerations.