There are a few different kinds of magic in the World of Darkness. Some, like the blood magic of vampires, is fueled by a source of power that the wielder can tap into. At the end of the day Gypsy magic is the same; it is the blood of Daenna in their veins that allows Gypsies to cast their magics, just like the blood of Caine flowing in the veins of vampires. Some magic is faith-based, and the practitioner’s faith and relationship with a higher power fuels the magic; the Red Order is an example of such magic. Some few individuals have learned to harness their own creative spark to bend reality itself to their will; these True Mages have no list of spells, but a common core set of building blocks, spheres of influence that they can use to bend reality. Such Mages can change reality with but a thought, and the universe trembles at their feet. But most practitioners of magic are not so lucky. For them, magic is a slow progression of learning rituals and rotes, a lifetime of study to cast a few limited spells. These are the Sorcerers, sometimes called Hedge Mages, and in this chronicle these are available to be played.
Hedge Mages are many and varied, and players are encouraged to look at the book Sorcerer, and the supplemental Mage book Ascension’s Right Hand to see what is available. There is no set list of differing schools of magic; players are encouraged to work with the storyteller to build the ideal coven of sorcerers that he would like to play a part of. Some schools are especially formal, and some are little more than the occasional gathering of like-minded individuals. Some mages are solitary creatures, learning all they know from dreams, while others study paths well-trod in ancient tomes and scrolls. It is unlikely that every magus will have access to every path of magic; Sorcerer lists 16 paths of magic; you should perhaps choose four or so that are common in your school of magic, four that are less so, four that are exceedingly rare, and four that are not taught by your school. Otherwise there is no personality to your school of magic, and all other Sorcerers you encounter will be as generic as you, and have access to the same spells as you. Let the parameters you set creatively define what makes your school of magic special.
Players may alternately play a Theurgist. The rules for this are effectively identical, but would use the Year of the Hunter: Inquisition book as the main source book. Note that most Inquisitors hate vampires; some explanation, such as an ally of the Obertuse, will need to be in place to make such a normal antagonist work in this setting.