In the main campaign mode, each campaign is divided into two to five chapters. For all but the last chapter, the goal of the players is to reach the safehouse at the end of the level, where fresh supplies of weapons, ammo, and health items are typically found. In the finale, the campaign comes to a climax and requires the players to either make a stand against waves of Infected as they wait for a rescue vehicle, fill up an escape vehicle's gas tank while fending off the horde, or race through a gauntlet of Infected to make their way to the rescue point.