The "rule" prominant in high school that allegedly states that if a teacher is not present in the classroom five minutes after the final bell has rung to indicate class has begun, the class may leave.

Although this rule has been tested, no conclusive evidence has been gathered to rule on whether this rule is real or not.
After sitting in the dark classroom for five minutes without a teacher, the majority of the class decided to follow the Five Minute Rule, so they got up and went to the cafeteria.
Get the Five Minute Rule mug.
When talking to someone of the opposite gender over some sort of electronic contraption, such as instant messaging, text messaging, or other alternate forms of communication, the rule states that if said person does not respond to a message in the time of five minutes, that they have either left, or are not paying attention to you. In most cases, this spells doom for relationships, but if your are talking to someone with a short attention span, this may be understandably excused with the necessary punishment of one minute of shunning.
Guy One: Dude, I was talking to that girl but she didn't respond for a few minutes so I used the five minute rule. I dont think she liked it.....

Guy Two: Yea, but its necessary to uphold justice in the social system....
by Artaxias September 8, 2009
Get the Five Minute Rule mug.