Houdini’s knot

The first person places his or her hands in the loops in one of the ropes, and holds it such that the second person can wind the other rope around it once. The second person then passes his or her hands through the loops in the second rope. From this position, you try to get free from each other without removing the loops from your wrists.

The trick has got its name from the famous escapologist Harry Houdini.