Magical traditions are methods and approaches that magicians in the world of Empire use to perform their magic. A tradition represents a shared set of guidelines that magicians can use to add additional significance to their rituals, not a prescriptive list of elements that must be included or your ritual will fail. The different traditions represent different ways of performing magic and while they are primarily useful for ritual magic, they have applications in spellcasting as well as crafting items.
Traditions in the Empire
The prominent magical traditions represent different frameworks, common ideas that magicians have shared that help them to wield magic. It is very common for a coven of magicians to use the established motifs and themes when working their magic; while some magicians develop their own unique approach to magic, using different symbols and words of power, most employ the tradition or traditions they were trained with.
Traditions may take different forms in different lands. The League is famed for the dramaturgy of its League troupes, with complex mystical symbolism for different arcane elements, but this is far from the only way to use storytelling and performance to create magic as the guisers, mummers, and cabalists would be quick to point out. Individual magicians find their own way to use the traditions to inform their magic.
Some magicians choose to concentrate on a single tradition, devoting their lives to mastering that approach to magic; others prefer to dabble, adopting whatever devices seem to best suit the magic they need.
The traditions commonly employed by Imperial magicians are far from the only magical traditions known; while the traditions of dramaturgy and astronomancy in particular are known all over the world in one form or another, many foreign magicians employ traditions entirely unfamiliar to the Imperial conclave. The Feni, for example, are known to use paint to create magical effects, using hides, the walls of caves and even people as canvas, while those who live in foreign lands beyond the borders of the Empire employ even stranger techniques.
It seems likely that the Thule, and the other barbarian orc nations have their own traditions, although little reliable information has ever been recovered and what little is known is confused and difficult to be certain of. The Jotun appear to invoke patron deities to perform miracles, while the Asaveans often invoke one of their dizzyingly wide variety of gods, demigods, household gods, and mysterious spirits when working their rituals. The Druj seem to make extensive use of complex herbal recipes to control their rituals, while the Axou apparently draw on the spirits of their dead ancestors to grant them power. In some cases, foreign magicians use entirely different names for the realms of magic themselves - for example both the Faraden and the Grendel - and disagree with Imperial magicians on the precise definitions of what those realms represent.
The magic traditions primarily exist to give players a basis for their roleplaying expression when performing rituals. Without a context for magic, it can be difficult for players to find sensible ways to phys-rep the magic they are performing. The traditions exist to give players a medium to roleplay the magic they are performing.
The traditions are also useful for letting magicians talk to each other about magic. They provide a common language with elements for magicians to reference and discuss.
Ultimately traditions exist to enable roleplaying - we don't determine which traditions can or should be used with different magics. We don't mark rituals, so there is no wrong way to use a magical tradition. The right way to use them is anything that reflects the philosophy of the tradition and improves the game for those involved.