A disentanglement puzzle invented by Rick Eason called Tricky Dick (available from Mr. Puzzle).
In the starting position, note from right to left:
the short fat rod, the loop of rope around the long rod, the metal ring, and the wooden puck.
The Starting position (left). Note the way the cord is threading through the ring.
Move the ring up through the loop (right).
Now move the ring up and over the long rod (left). Bring the ring back down through the loop (right). After passing through the loop, bring the edge of the ring that is toward you upward. The ring should still be around the rod.
Move the top of the ring back over the top of the long rod (left). The ring should now no longer be around the rod. Move the ring downward over the short fat rod (right). Look for the loop of cord from the puck passing down through the loop, around the ring, and then back up through the loop to the top of the long rod. If you don't see this loop then you have done something wrong, backtrack!
Move the ring onto the long rod, through the loop (left). The ring should now come off (right). Congratulations, you have solved the puzzle!
To reset, reverse the solution steps for the next victim.