imagine if one day you came into school and there would be 5 groups in the class. Each one of them had their own character sheet with an information about the character which they are in control of. You would pick the name, place in the world and what does he or she does. Some information might be chosen by the teacher if it would be needed, like the time in which the person lives.
I am thinking up some random rules that I thought would be interesting.
For example, the character would have certain amount of energy and it would sleep well only if you would solve some math problems. Teacher has in curriculum to talk about how the people lived? No problem, it is winter and they need to get clothes (maybe the sellers speak in English) but the groups do not have enough money so they can either teach the seller how to write (because for some reason that is exactly what he needs) or they must find how to get money, maybe by painting pictures about what happened so far or helping design a bow or even build a prototype. Because everybody needs to eat, they will go to forest and learn about plants that are useful for eating and maybe even cook a food and decide if the character liked it or not. On the road, they meet a traveler and they need a water from him because it is a dry season, he has it but needs information about the situation in kingdom. Because they are so far away they need to write a letter to their parents about what happened, of course it needs to be grammatically correct. Finally, after completing their quest they can use the time machine and move into different era, maybe they want to meet with people from their parent’s generation or see a tyrannosaurus rex.
My point is, I personally would be so much engaged in something like that! I am not necessarily proposing it as a true model for schools but I find it to be creative solution to many problems in school though some might still stay, what if a kid is not happy with the character or with the style of RPG? (Well not that many kids like the system these days.)
The thing is that it is an adventure, not just sitting in a school and writing down notes, you are living what you are learning and I would learn german if it was either my character lives or my character dies.