For questions about Prusik knots and their use. Please use [ascender] tag for mechanical rope-climbing devices.

Named after Austrian mountaineer Karl Prusik. A prusik typically involves looping a thinner diameter cord around a thicker cord or rope. In this way the prusik can grip the rope or cord. Prusiks only "grip" the rope when loaded, so they can be slid up or down a rope. They are generally used for ascending vertical rope or as a back up to a belay device (i.e. if the user of the belay loses their grip the backup will prevent the rope from feeding unhindered)