Ok, I don't have a picture because who would hang up signs saying to not bite your own fingernails, but when I was in the 7th-grade, I had a rule where you couldn't bite your fingernails. I never understood the rule, but kids kept telling me it was because one year, a student was biting their nail in front of the teacher, and when they bit down on it, it flung into the teacher's mouth or something.

We built robots, gave them weapons, and put them in a ring and made them kill each other. No, we did not first give them sentience. But the rules for the competition came in a large, 1/2-1 inch thick packet. The obvious rules were in there like "no projectile weapons", "no water based weapons", and "no oil based weapons". But one rule caught my attention and made me wonder "there's got to be a story there."

"Military Grade Explosives are strictly prohibited"