Famous Gaming Laws Axioms and Principles

The Stafford Principle: Maintain a sense of wonder in the campaign. Make sure there is always some surprise or something special that makes a session, an adventure, a campaign and your whole world unique.
Perrin Principle: Be consistent. If you do something once, it becomes a precedent. The players will remember it, and count on it being the same next time. If it's not the same later, have a darn, good, obvious reason for the players that it's different.

Petersen Principle: Make it fun. Don't be afraid to change a plot to go with player enthusiasm. Try something crazy or goofy, even (or especially) in serious settings. Roll with the mood and make it happen. Be high energy!
Sandy's Axiom: Involve at least three senses in every scene. These can be described or experienced (e.g. props, incense, etc.). People have five senses, and adding details about weird sounds, the unusual smell or the texture of something adds to the gaming experience.
Tucholka's Law: Players will always do what they want, so know all the world background material well enough that they can never go places or do things that you are totally unprepared for.
Aaron's Principle I: Always listen to your players. They will constantly be analyzing, theorizing, and commenting on the adventures. Often, their discussions will give you even better ideas than those you have been implementing.
S. Jackson's Law—If a player has found an exploitable loophole in the rules, congratulate the player on their ingenuity and ruthlessly disallow it.
Levekius' Law: Make sure everybody understands that you need to give to get. Nobody can come here and just suck everything without giving back in creativity, time, politeness, money, transport, book, etc. Everybody should invest time and effort in this campaign in one way or another. Flush the people who do not.
Robin's Law: If you and your players are having fun, you are a good GM.

Sandy's paradox: Consider any rule absolutely inviolate, until you reach a point where you understand why you shouldn't break it. At which point, you can break it when you feel you need to.
Fitzpatrick's Law: Pay attention to your players. Listen to them. Watch them. Don't let them get bored. Give them what they think they want, but make them work for it. Let them go on their own paths. Just keep an eye on their responses and be ready to step in.

Oh, yes.. One more...

MoonHunters law: Better games come from better gamers. All members of the troupe should strive together to make the best game possible.