In a magically-oriented FC, this comes up from time to time. 
In general, most people seem to stake out what they're good at and what they're bad at magically, and that provides some basic limits. Beyond that, for us, the further afield from "what you see in game" a person tries to do, the more difficult it is and the more preparation, experimentation, and research are typically required to construct and cast the spell. This jives with Mysterium's generally "Hermetic" feel and arcanima slant, where magic is a matter of both talent and knowledge.
Within this framework, there's not really a limit to how many spells might come about, other than the OOC limitations of story plausibility, explicit lore, fairness to your fellow players, and consent. We've had modified Sleep spells to calm people down, barriers of elemental aether, arcanima-boosted fire magicks, and so on.
In general, most people seem to stake out what they're good at and what they're bad at magically, and that provides some basic limits. Beyond that, for us, the further afield from "what you see in game" a person tries to do, the more difficult it is and the more preparation, experimentation, and research are typically required to construct and cast the spell. This jives with Mysterium's generally "Hermetic" feel and arcanima slant, where magic is a matter of both talent and knowledge.Within this framework, there's not really a limit to how many spells might come about, other than the OOC limitations of story plausibility, explicit lore, fairness to your fellow players, and consent. We've had modified Sleep spells to calm people down, barriers of elemental aether, arcanima-boosted fire magicks, and so on.
The Freelance Wizard
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
