A while back, a friend asked me about devising some Spell Drain rules for Novus (as opposed to Spell Points).
Essentially, spell points are a way of having a hard limit on the number of spells that can be cast in a given time frame.
Spell Drain, however, represents a soft limit on the number of spells able to be cast...
So far, I have identified 2 types of resolution methods (Save vs. Drain and Single Roll), and at least 3 types of Drain (hit points, Spell Points, and Spellcasting). A little more detail follows:
Save Vs. Drain -- this is essentially adding an extra roll to the spell casting process, making the player roll a saving throw against the spell he just cast or he takes Drain.
Single Roll -- This works more like the same way that spells vs. DEF work, it simply adds another number for the same roll to be compared against (i.e. roll, if it beats the CTN, the spell is cast as normal, if the roll is higher than the Drain Threshold (which is higher than the CTN), the spell is cast without any Drain at all).
Hit Points -- with this, the Drain is from the caster's hit points. However, this has the drawback of encouraging mages to be be buff and have lots of hits. A really bad roll can mean that the mage takes a lot of hit damage from the spell... These hits would heal normally.
Spell Points -- This pulls from Spell Points - the thing is that this means that the number of Spell points used becomes variable, (on the low end of a casting roll, we would put a limit of double the # of SP required by the spell as the max drain for any given spell, prior to Snag Points being used) -- spell points would be recovered normally
Spellcasting -- essentially, this gives a -1 to the spell casting roll for the Drain. So a spell would cost either a -2 to Spellcasting for a failed spell, -1 for a successful spell (under Drain Threshold), and 0 for above Drain Threshold (Boon points could be used to erase the Drain as well...). The downside to this is that it puts the character on a downward spiral for spellcasting, each instance of drain making further drains more likely.
Now, my question is ----
Should I pick 1 method for Spell Drain, or should I make it a matrix of options (choose 1 resolution method, choose 1 drain type) that the GM selects from?
Opinions? Comments?