At long last, the final installment of the Harry Potter franchise, Harry Potter and the Deathly Hallows (Pt 2) is hitting theaters tomorrow. I'm sure by now most people who game have either seen the movies, read the books, or like me done both. It may just be me, but when I first experienced these stories I saw alot of good characters and concepts (especially horcruxes) I wanted to use in a D&D campaign. Indeed, never since the Hobbit has supposed "children's ficition" moved my imagination this much. Yes, I am talking about the feasibility of running a wizard school campaign in Greyhawk! Crazy you say, grognards? Perhaps. But all the information you need to build one is there in canon, all you need to do is to pull it all together:
When running a magic school like in Harry Potter, you need a host of characters. The teachers are a good place to start and luckily there are a few in canon already:
Kieran Jalucian (Principal and also Guildmaster of Wizards) (Wiz 21)
Tobin Potriades (Senior Tutor from 576-591 CY)
Abrazaldin Hosk (Senior Tutor 591-present) (Wiz 20)
Darnak Khorshan (Head Porter, both the university and the Guild of Wizards have dwarven security) (F6)
Ephraim Blackrod (Master of Ceremonies, a ceremonial title but does hold real power in the school)
The first reservation most gamers would have is playing children. In Harry Potter they start at Hogwarts at an awful young age but the school encompasses several years and age groups, thus by the end of the saga the main characters are respectably matured enough to be decent adventurers. This in mind, a DM can adjust the starting ages for his wizard school along with what the players are comfortable roleplaying. I can speak on this through experience; I ran four full game years of a "hero high school" campaign using Mutants & Masterminds and if you gradually adjust the game from a non-lethal "light hearted" storyline to a "darker" more dangerous one, the age of a young PC really doesn't matter since most of the action occurs among peers of their own age. If you follow the Harry Potter stories, this is how things progress.
Now one of the first logistical problems of younger characters is they aren't physically or mentally on par with the adults that they encounter at their school. There are a few solutions to this. First, in the hardback AD&D book Greyhawk Adventures, there is an interestingly extensive ruleset for playing "0-level" characters. Apprenticing characters using this must train and build their skills and attributes all the while under the tutelage of an instructor. Even alignment is formative with morality and ethics being tracked in this 0-level system. Perfect! A less intensive way to handle the age disparity (as we did in M&M) is to simply lower the baseline attribute for point buy characters. As the character ages (at whatever rate the DM determines), these stat points raise back up until they are considered typical "young adult" PCs. There are other perks you can give for aging up to young adult such as a few extra skill points, feats, or whatever the DM can imagine. Also remember, most editions of D&D have optional rules for "level training", that is you are not allowed to actually raise a PC to the next level until time and money is invested. These systems would be good to look into for simulating the time and energy spent in the University.
An All Wizard Campaign
Some players might blanch at the thought of everyone playing the same class since it lacks the balance needed for a traditional D&D game. Being a wizard in Harry Potter is common but in Greyhawk it is not. This is problematic but not a total loss as long as the first couple years of apprenticeship takes place inside the wizard school environment. All a clever DM has to do is tailor the plots and obstacles toward a group of wizards, and since most things inside a well regulated wizards school are not out to kill the PCs even low hit point wizards don't have to perpetually worry about being slain. Once the PCs are allowed to leave the pyramid and roam the city or beyond, is when they may begin multi-classing and occasionally taking on non-spellcasting companions. Yet, everytime they return to the University the stories will certainly center on wizards.
Main villain? Guh! Do I have to do all the work? How about a student sponsored by the renegade Seeker, Eli Tomorast? That would set the PCs up for a lifelong enemy!
Essential sources for the University: City of Greyhawk Boxed Set (1e/2e), Greyhawk: The Adventure Begins (2e), Living Greyhawk Journal (issues 4-5), Greyhawk Adventures (1e/2e) and one last book, College of Wizardry (2e). I never owned this book, but if any accessory was ever written with this type of campaign in mind, this has to be the one.