Is it too easy to cast powerful spells with RPM?

[Varyon]

Originally Posted by mlangsdorf

The easiest solution is probably to limit the maximum skill levels via GM veto - "no, you can't have any Path skills over 19, and you can't have more than 150 total skill across all your Paths" or whatever suits you best.

Something this made me think of that might help would be that a Grimoire, rather than just giving a static bonus, gives its normal bonus up to a certain final skill level, then is reduced beyond that. Perhaps a typical Grimoire gives its full bonus up to skill 15, half bonus up to skill 20, quarter bonus up to skill 25, and so forth. So, if a character with skill 13 grabs a +4 Grimoire, that's good for +2 to get to skill 15, but then the remaining bonus (+2) gets cut in half (to +1), for an end result of skill 16. For our skill 20 character, that +4 Grimoire has its bonus reduced to +1, for only skill 21 (total 24 with Grimoire+Ritual Mastery+workspace). The idea here would be that, the better you are, the less useful a guide is. More expensive Grimoires that don't suffer any reduction until skill 20 might be available - and they probably require some minimum level of skill to actually make use of, as they contain markedly more advanced information.