Was thinking of creating this sometime ago. I was thinking of making a RPG centering around youth crime, and also how the city it's based in is affected by it. Here's a few examples of crime:

Underage drinking
Possession of illegal substances
Usage of illegal substances
Illegal fighting, etc. All the way up to organized crime.

Profanity will be allowed of course. And you don't just have to play as a teen -- you can also play a role in the community as a teacher, parent, good teen, shopkeeper, police officer, etc. Gangs will be allowed... And, well, committing crimes. However committing them won't get you off scotfree, since there will also be certain programs within the city you could get sent to if caught. A school will also be included but it'd be possible to skip school, but you risk getting sent to it if caught.