GURPS Shadowrun

[Kallatari]

Originally Posted by Crakkerjakk

I think I already mentioned this in this thread, but a nifty way to mimic the variable drain from casting in SR is to allow fatigue reductions based on margin of success instead of absolute skill levels. Thus it's variable, but encourages high skill levels. You can start it at 1 FP/5 MoS, and vary the ratio to make magic more on par with guns. For my games I found the sweet spot to be about 1 FP/3 MoS.

That's pretty much what I do, except that I reduce the energy cost by 1 FP per 2 points of success. I even created a new Cost Fatigue (Margin-Based) limitation to allow me to make powers and abilities along those lines. I've been using this house rull for magic in all my campaigns for the past couple years, and it works pretty well.

In my Shadowrun conversion, specifically, to represent physical drain, what I did is that one-half of the energy cost, rounded down, is paid for with HP instead of FP (or energy reserve). On a successful roll that reduces the energy cost, it's the HP cost that is reduced first.

For example: You have a spell that normally costs 5 energy to cast and 3 energy to maintain. In my conversion, it therefore costs 2 HP and 3 FP to cast, and then another 1 HP and 2 FP to maintain each minute. If you succeed your skill roll by 2, this reduces the cost to 1 HP and 3 FP to cast, and 2 FP to maintain. A margin of success of 4 reduces it to 3 FP to cast and 1 FP to maintain. A margin of 6 makes it 2 FP to cast and no cost to maintain. etc.

Although I didn't use this particular rule all that long as I only had a single "Shadowrun" adventure in my campaign (it was a world/dimension-hopping adventure from my normal primary campaign setting; I ruled the HP cost for casting spells to be a setting effect), for the time it was there, it seemed to work rather well. My spellcasters certainly weren't throwing spells around at will unless they knew it at a really high skill to ensure no damage was taken while casting.