Carl's trap-farming skill: pick up an enemy trap and deconstruct it for reusable materials.
Backfire is a rare skill granted by Carl's Compensated Anarchist class (at +5). It lets him pick up an existing trap and deconstruct it, salvaging the materials — especially the valuable triggering mechanisms — for his own traps and bombs. Mordecai notes a crawler could make a living just farming traps with it, making it one of the standout perks that drew Carl to the class.
Carl's resource-generation skill for his trap-and-bomb build.