Effect: the magician put a puts a piece of rope over his/her neck and ties it and is pulled and goes through the neck
secret: when you use the rope make sure the left size is longer than the right and grad the left side with your right and and right side with left. the pull the left side of the string about an inch over making sure the end of the rope is left of your body. then lift the rope behind your head not letting go and once the rope catch is behind the neck pull the end of the string and it releases the catch and it looks like the rope has gone through the neck
if stuck check out this youtube video?
p.s. this is the trick but not my video