A few friends wanted to play a Harry Potter ttrpg but, neither them nor I, had any time to prep the game, write a campaign or anything.
So here is my solution !

https://domergue.itch.io/hogwarts-express

Hogwarts Express is a ttrpg requiring no prep at all, using a minimalist ruleset, a bunch of six-faced dice and A LOT of guided improvisation and randomness.
Built upon the Hopes & Dream system.

You play as a group of Hogwarts students, in any time period you want, against any kind of vilain you can imagine. It could be a small scale story with a mean bully, or a grand adventure against the deadliest Dark Mage you can muster. Voldemort, Grindelwald or even your own creation.

Welcome back to middle school. This time around, it’s magic !

Source: itch.io