Back when I was in school we ignored most of the rules while playing Yu-Gi-Oh, you didn't need to tribute to summon monsters above level 5, you weren't restricted to x number of cards of certain types in your deck, stuff like that.
It was just all the cards we could use and about 12k lifepoints, stuff was fun.
Only because my deck was nothing but man-eater bugs, monster reborns and a single 3k attack point monster :p