Instead of leveling up by gaining experience, you must complete certain requirements to reach the next level.įor more information, see: Killing Floor: Calamity Perks Medic was also renamed to Field Medic, and Support became Support Specialist. They also added two new perks with Demolitions and the Firebug. The retail release of Killing Floor had all the perks unlocked from the start, but they could now level up (from level zero up to level six). You first had to unlock each individual perk by completing a task, and the perks did not level up. The original versions of the mod had no perks, and when they were eventually added they did not function quite like they would in later games. For more information, see: Killing Floor Mod Perks