Zombie apocalypse is a subgenre of apocalyptic fiction in which society collapses under swarms of zombies and only small bands of humans survive, a genre that first emerged in 1968 and returned to popularity in the late 2000s. Outfits drawn from it stay casual, with military or tactical elements folded in. Cargo pants cover the bottoms. Military jackets go over the top. Military green runs heavily throughout, and the clothes are distressed with rips and stains.