Rule 34.5 

If it exists, there's a Minecraft mod about it.

A: Wow. I never knew that there was a Minecraft mod about it.
B: Dude, rule 34.5

Rule 34.5 by goose141 January 8, 2021

Rule 90 

Everything is better with zombies.

Rule 90 of shopping malls? You got it.

Rule 90 by Capitain Jay April 26, 2008

Rule 0 

The unwritten rule of tabletop Role Playing Games:
The Game/Dungeon Master has the right to veto anything any player says, he has the right to change any rule or make up his own, he need not explain why he choses to do these things. If players complain the GM may choose any of the following to do to the player; slap, call a dumbass, restrict snackage privileges and/or threaten injury to ingame character(be it through loss of xp, health, items or gold)

Player: Can I make my own species for my familiar
DM: Hells no! I'm gonna have to Rule 0 that one
Player: Bitch
DM: I swear I will cut you off of the mountain dew boy
Player: I'm sorry master.

Rule 0 by Cecil Helden December 28, 2007

rule of thumb 

one of the most commonly misconstrued sayings, an example used in Boondock Saints "a man is allowed to beat his wife with a stick no thicker than his thumb." A claim made by a satirical caricaturist by the name of James Gillray against a judge. The first and original use of the saying is as simple as the words. The thumb was used as a readily available tool of measuring. Such as the Tailor's rule of thumb "the circumference of the thumb twice, is the circumference of the wrist, twice the circumference of the wrist is the circumference of the neck, and then twice the circumference of the neck is the waist's circumference." Then there is the Brewer's rule of thumb where if the temperature of the wort wasn't insufferable by the thumb it was cool enough to pitch the yeast. It has now been used as a term of commonplace knowledge in a field.

"The rule of thumb in making a sale is confidence, without confidence you don't make a sale"

rule of thumb by atleastvisitwikipediaorreadadamnbook February 21, 2008

rule of possession 

If you own it, it sucks.

"Your dog is so cute!"
"Yeah. You don't live with it. Rule of possession."

rule of possession by Jade J. January 7, 2009

Rule of Puberty 

The rule saying that if you date an ugly/not so attractive girl before the rest of puberty hits, she will be hotter later on and you will still be dating her, resulting in your success and the envy of your friends. Has a 9/10 success rate. Can also be applied to dudes.

Doug: "Ew man why is Johnny dating Jill, she isn't even hot"
Jim: "Rule of puberty, dude"

*1-2 years later*

Doug: "I would totally bone Jill now, too bad she's still dating Johnny"
Jim: "Told you man"

Rule of Puberty by EpicMamo September 24, 2013

Rule MLP 

An internet law that states that if something exists a crossover or parody of it using content from the show My Little Pony Friendship is magic exists.

mediums that often contain material pertaining to Rule MLP are: Fan fictions, fan animations, internet memes.

Rule MLP by N&R Internet detectives January 15, 2014