The Rubber band gun has three functions. The most widely used is as a weapon for taking down large enemies, as it will wrap them in a rubber band, making them vurnerable to attack and kill. The second is as a grappling hook, as holding the fire button on certain objects will make one half of the rubber band attach to something, allowing you to "bungee" to that point. The third function is much like the grappeling hook, nut if attaching it to two points will create a tightrope that Skitter can walk on. If you manage to somehow lure an enemy into a tightrope, it will act as a tripwire.