Felltower - Improved Magic Resistance in DF Felltower

In DF Felltower, we run Improved Magic Resistance differently than by the book.

Magic Resistance works as written.

Improved Magic Resistance provides a +1 per level to resist hostile spells and a -1 to hostile, resisted spells cast on the character. IMR doesn't "know" a spell is hostile. If a spell normally allows for a resistance roll, it provides the -1 / +1. If not, it does not. It has no effect on elixirs - hostile or otherwise - and no effect on spells or magic items used by the character with IMR.

Some of this springs from a misunderstanding we had from back in the day about how Improved Magic Resistance was intended to run. For DF Felltower, I just kept up that ruling as I feel it makes for a better tool for wizards.

This should cost a bit more. You lose the ability to shrug off hostile elixirs, but most of the time it's pure upside unlike the mixed upside/downside of Magic Resistance and by-the-book Improved Magic Resistance. Still, 5 points for a +1 Will or HT for spell resistance only seems fairly priced by the eyeball pricing approach. You could probably bump it to 6 or 7 points a level with the -1 to hostile spells, but I figured I'd leave well enough alone. The lack of a -1 per level to spells you don't want on you but which aren't resisted seems a solid tradeoff for that.

GMs using the Antimagical Bracelet from DFT3 (p. 13) may wish to use the above version of Improved Magic Resistance for that item only, to get a true feel for how it operates in DF Felltower.