Kissing don't last

8. Nominal Rule
Any character who actually has a name is important in some way and must be sought out. However, if you are referred to as a part of a posessive noun ("Crono's Mom") then you are superfluous.

156. Sephiroth Memorial Escape Clause
Any misdeed up to and including multiple genocide is forgiveable if you're cool enough.

184. Adam Smith's Corollary
No matter how thoroughly devastated the continent/planet/universe is, there's always some shopkeeper who survived the end of the world and sits outside the gates of the villain's castle, selling the most powerful equipment in the game, like nothing ever happened.

191. The Ultimate Rule
Anything called "Ultima (whatever)" or "Ultimate (whatever)" isn't. There's always at least one thing somewhere in the world which is even more.