Basically, someone says something they did (Can be real or fake) and the person below them says if that is a success or a FAIL. Ex. P1: I crashed my car on purpose for a funny video! P2: FAIL! I made up a new yo mama joke! P3: Success! etc.
FAIL! I play soccer, and it's really fun! It's better than baseball and football, at the very least; there's waaaaaaay too much stopping in those sports. I've watched a baseball game; they swing once, then stop for 20 seconds! Football: they run a play, then stop for 30 seconds!