To pull someone’s leg is to tease them, often by telling a playful falsehood and waiting to see whether they believe it. The expression can also describe a harmless attempt to fool someone, rather than a physical prank. Its history is less tidy than its meaning: the earliest reliably known appearances in print date to the 1880s, and the phrase was already being used in its familiar joking sense. That gives us a useful boundary, not a birth certificate. The records show the idiom was in circulation by that decade, but they do not reveal who coined it or exactly where.
The image is easy to picture: someone gives another person a tug and makes them lose their footing. From there, the phrase may have become a comic way to describe making someone stumble socially—by misleading them for a laugh. That is a plausible explanation, not a proven account of the phrase’s creation. The figurative meaning is what the early printed evidence supports; it does not establish that the expression began with a literal act of tripping.
A popular story attributes the phrase to 19th-century street thieves, who supposedly pulled a victim’s leg to make them fall before robbing them. It makes for a vivid origin tale, but there is no reliable evidence connecting the idiom to that practice. The story also offers a more elaborate explanation than the surviving record can justify. Since the phrase appears in print as a way of joking with someone, a simpler possibility is that its physical image of a stumble made a natural metaphor for being fooled.
The meaning has remained remarkably steady. Today, pulling someone’s leg usually means teasing them without serious malice, though the joke can briefly leave the listener unsure what to believe. “You got the promotion already? Are you pulling my leg?” someone might ask. Or: “I told my brother the dog had learned to open the fridge, but I was just pulling his leg.” The phrase endures because it turns a familiar bit of physical foolery into a quick, playful way to describe being taken in.