Rule of 72 

If you don’t practice something hard in 72 hours (3 days), you will forget it

It’s Sunday. I haven’t practiced the Rubiks Cube since Wednesday. I sit down and think: How the hell do I do this thing? Then I realize I haven’t practiced in 72 hours. I think ‘Oh... Rule of 72.’

Rule of 72 by Irreduzibel November 11, 2018

Rule C Corollary 

If it doesn't exist, you can also sell it.

God, Pokemon, the futures of the next generation, you name it. Rule C Corollary.

Rule C Corollary by mothinflame123 November 18, 2018

rule 899 

Rule 899 is rule 93. Still, I found it.( ͡° ͜ʖ ͡° )

HAY GUYS I FOUND RULE 899 ^_^

rule 899 by dhh777 December 26, 2018

rule 34r 

a variation of rule 34. if it exists, there is a subreddit for it

person 1:have you read (insert anything here)
Person 2:no, but i just found the subreddit for it
person 1:how?
person 2:because rule 34r

rule 34r by gasman7 January 21, 2019

Rule 35 

Similar to Rule 34 in the idea that "If it exists, there is..." Rule 35 means "If it exists, there is a -chan"

"Earth-chan, Black Hole-chan? What are these?"

"Oh, that's just Rule 35 at work"

Rule 35 by MrFeelsGooda May 6, 2019

rule of kewl 

If something is kewl, it shall be overused

Dan: that new song is so good
Me: rule of kewl

Dan: Wtf?
Me: it’s gonna get overplayed

rule of kewl by #s r = 2 letters July 17, 2019

Rule #3646 

The life handbook rule that states not to rub Vick's Vaporub in your eyes.

Tony: I applied some Vick's but then rubbed my eyes. They burn bro!

Jack: Rule #3646, bruh.

Rule #3646 by El Massivo September 3, 2019