A made-up rule where people who are 40 years old or older get to use the rule as a response to anything they don’t want to participate in.
Travis: “Hey Tristen, look at this!”

*Tristen looks down at Travis’ hand, and sees that Travis has made the Circle Game sign. *

Tristen: “No man that doesn’t count, The rule of 40 bro”
by The A-Team February 03, 2018
Get the Rule Of 40 neck gaiter and mug.
The useful and highly strategic approach to lectures/class in university. By going to class you must take 50 mns worth of notes as opposed to later copying said notes in let's say 10 minutes. 50-10=40. Hennings rule of 40
You going to that shitty law lecture Sam?? Nah, ill just use Hennings Rule of 40
by TheRelentlessBagel October 31, 2013
Get a Hennings Rule of 40 mug for your mate Manafort.
Rule 36 states that "if it exists, it is someone's fetish", not Rule 40. Read the rules of the internet, newfag.
by loooooooooooooooooooongcat February 25, 2008
Get a Rule 40 mug for your daughter-in-law Riley.
Kenjito: Simmilar to Rule 34, it states "if it exists, it is someones fetish"

longcat: Rule 40, newfag
by sethkasketch December 26, 2008
Get a Rule 40 mug for your guy Trump.
If it exists, there is Dubstep of it. No exceptions.
"I can't watch Teletubbies any more thanks to Rule 40. All I can think of is wub wubs now."
by Sullavin April 26, 2012
Get a Rule 40 mug for your friend Zora.
Simmilar to Rule 34, it states "if it exists, it is someones fetish"
person 1: "i wonder if anyone has a (insert anything here) fetish."

Me: "RULE 40 DUMBSHIT!!!!!!111ONE"
by Kenjito February 17, 2008
Get a Rule 40 mug for your daughter Larisa.