The School Rules are, as the name implies, rules that the Principal of the Thing enforces at Here School. While it is not required to follow the rules, if the Principal catches the player not following them, he will relentlessly pursue them, and when he catches them, put them in his office for detention. The School Rules are:
- No running
- No entering Faculty
- No bullying (If the Principal of the Thing sees It's a Bully or spots the Player cutting Playtime's rope or 1st Prize's wires with the Safety Scissors) (used to be no eating before Update V1.3)
- No drinking
- No escaping detention
- No fourth wall breaks
- The player can break the fourth wall in Baldi's Basics - Field Trip, which will also trigger one of his originally unused lines. however, Principal of the Thing will not send them to detention for it.
- The no fourth wall breaks rule may be a reference to the Meta Game Jam metaness categories, as one of them is named Breaks The Fourth Wall or normal ressecs.
- Within the game's files, there are unused voice clips of the Principal of the Thing saying "No stabbing people with pencils in the halls!" and "No looking in other people's lockers in the halls!", meaning that there were going to be eight rules to follow at some point.
- The Principal's Keys were originally just called "Keys", which could point to the fact that the keys might have originally been used for one, if not all, of the lockers instead.
- In the the earlier versions of the game, there was a rule against eating in the halls, which was removed since update V1.3.
- This was most likely changed due to lack of sense.