The Slap Bet
- The Story: Marshall and Barney make a bet that Robin was a stripper named Robin Sparkles, and the winner gets to slap the loser three times as hard as he can. Marshall wins, and Barney ultimately agrees to get five slaps spread out over all of eternity. This later becomes eight slaps after Barney makes a trade for wearing the Ducky Tie.
- Where We Left Off: Seven slaps have occurred throughout the show's nine seasons, with the final slap still saved for the end of the series.
- Final-Season Status: There was a big episode dedicated to Marshall learning how to slap properly, and the final slap happened on the March 24 episode. What did Marshall save it for? Slapping some sense into Barney at the altar when the groom tries to flee.