When people are playing a game, they need to follow the rules. If they don't, the game becomes disorganised and unfair, and it stops being fun. If a student ignores a rules against talking in class,the other student can't concentrate. Driver who don't follow traffic laws can cause serious accident.
Most things we do are governed by rules. These may be unwritten, like the rules of social politeness, or official laws passed by parliament and backed up by the legal system. Punishment for breaking the rules may vary from being criticised to being put in prison. But all rules and laws have the same purpose - to make it clear what most people agree is right or wrong, and what happens if someone breaks the rules. They are disorganised to ensure fairness, safety and respect for other people's right, and in this way they help us work, play and live together peacefully.