Basicly the person has to slap the person before them for something so for example:
Person1: I slap you because you don't like cheese.
Person2: I slap you because you like COOKIES I win 8D
Person3: I slap you because you didn't win I DID
It is basicly a friendly way of slapping people 8D
I'll start. I slap you because there is no post below me therefore I slap myself -slaps myself- OwO