[Gnome]

My big mistake when first trying RPM was introducing it in a game where only one PC was a mage. About 75% of game time was spent with everyone watching that player do stuff: making rolls, proposing new rituals that could solve whatever predicament the party found itself in, determining effects and interactions, strategizing ways magic could solve problems, deciding whether a certain ritual was "fair" or whether the rules support it, etc., etc.

A lot of this was bad GM-ing on my part, of course. I could have just cut that player off every time and tried to come up with reasons to say "no, you can't do that because...", and eventually I told him he can only cast rituals in-game that we had already previously agreed upon (this weakened the mage significantly, which didn't really matter because he remained many times more powerful than the other party members), which helped.

I also tried to simplify RPM by not including charms. This too was a mistake, as many people here on the forums pointed out, because a big part of the balancing factor for RPM seems to be the existence of other mages who can dispel your rituals or turn them against you, and they need to be ready to do that with charms if it's an action-packed type of game (this was meant to be an Indiana Jones style pulp action campaign).

I kind of gave up on RPM after that. I've had a lot of luck with the standard Magic system, having used it for decades now. It's actually part of what originally drew me to GURPS. I have had no difficulty modifying it for various games by excluding certain spells, writing lots and lots of new spells, and using some of the many good suggestions in Thaumatology for modifying the basic system. Some of these modifications can create a totally different "feel" to magic and make it suitable for all kinds of games.