Pull Someone’s Leg

The original leg-pullers, were, it seems, by no means so harmless as their modern counterparts, the practical jokers.

In the late 19th and early 20th centuries, muggers and street criminals were sometimes known as ” trippers up “, through their practice of tripping up their victims before going through their pockets. So it seems likely that to pull someones leg was originally to trip them up and rob them – far from the sense that expression has today.