A person says a thing, another person says a thing that is wrong but sounds similar and is plausible and rhymes or is in some way a pun. Then the next person responds similarly but instead of their response being similar to the original comment it is similar to the second comment but dissimilar to the same degree as the second comment was from the first. Then another person will do the same thing but to the third comment and-so-on-and-so-fourth until no one can think of a way to continue.

It is both funny as you read down the comment chain, and also, interesting when you get to the bottom and note how different the posts at the bottom have become from the original.

I don’t think I’ve ever seen somebody actually explain it before and I hope I haven’t ruined it by doing so… Or rather, what I really mean is, I hope you haven’t ruined it by making me do so.