(S04E21) Perhaps this dates me a bit, but I remember an episode of M*A*S*H where Charles basically played both sides of a practical joke war between B.J. and Hawkeye, and ended up having the joke be on him in the end. That episode was what came to mind as I was watching this one, which was amusing but by far the least funny HIMYM episode in quite awhile.

The practical joke plot, with someone always being in the middle, is an old saw of the sitcom biz, and Bays and Thomas pulled it out of their bag of tricks this week. They tweaked it a little bit, though; this became more of an exercise in Marshall and Barney teaching Ted a lesson that ended up going way to far, and everything seemed to work out for Robin, who was the middlewoman. But it was familiar enough that it had the ghostly imprint of sitcoms past on it. And when that happens on this show, it's never good.