“How I Met Your Mother” turned 20 years old in 2025, and it still holds up, partly because of its string of long-running jokes between Ted Mosby (Josh Radnor) and the gang — whether it’s Robin Scherbatsky (Colbie Smulders) being a Canadian teen pop star, or the military salute whenever a character uses “general” in a sentence. While the CBS show is one of the best sitcoms ever made, none of the gags was better than the supremely funny slap bet.
Before Robin’s pop star past is uncovered in Season 2, Barney Stinson (Neil Patrick Harris) and Marshall Erickson (Jason Segel) bet they can discover what her secret is, agreeing that the winner gets to slap the loser. Ultimately, this escalates and Marshall has five slaps to use throughout the series. But CBS executives weren’t keen on the concept.
In a retrospective feature about “How I Met Your Mother,” writer Matt Kuhn told Entertainment Weekly, “The studios at the network were not excited about the slap bet as an idea. They were nervous about the silliness of it, and it’s one of those things where you’re like, ‘Well that’s what makes it fun is that it’s so stupid.'” The slap bet last lasted from Season 2 in 2007 all the way until Season 8 in 2014.
The slap bet started from a high school friendship
“How I Met Your Mother” showrunner Carter Bays revealed that the slap bet was inspired by something he did with a close friend when he was younger. Bays explained, “A friend of mine from high school, we would slap each other occasionally. Slapping in high school was our way of having fun. The idea of slap bets definitely came from that era in my life.”
Matt Kuhn also explained the excitement of knowing they could make the slaps into a long-running bit for the series, saying, “When we ended the first slap bet episode, and it was left with the five slaps for eternity thing, 99% of the joy of that episode was just knowing we’re going to get to come back to this in the future.” Marshall delivers the next slap in Season 3, Episode 9 — our top-ranked “How I Met Your Mother” Thanksgiving episode. Kuhn couldn’t remember why they chose that episode in particular but joked, “Someone probably said the word ‘slapsgiving’ and that’s when everything fell into place.”
Neil Patrick Harris said he was onboard with being repeatedly slapped during “How I Met Your Mother” because he and Jason Segel were extremely competitive, and he described himself as a “rabid fan” of the slap bet. It’s lucky that he enjoyed it so much, because Marshall slaps Barney a total of eight times throughout the series.
