Help making Powers and Threshold Magic work together

[mlangsdorf]

The normal energy cost to cast or maintain a spell is applied to the tally (Thaumotology p 76). When tally accumulates to be more than the threshold, a calamity might occur (Thaum p 77).

Mana level effects Threshold magic normally: magic cannot be cast in a no-mana zone, spells are at -5 to cast in a low magic zone, people without Magery can cast spells in a high mana zone, and tally is refunded on a successful cast in a very high mana zone but all failures are critical failures. By default, mana levels do not adjust tally, Threshold, or Recovery Rate.

If you're creating magic as powers, then use Nuisance Effect: adds 1 tally (-5%) in place of Costs 1 Fatigue (-5%). It's up to you how much tally any particular spell incurs.

As always when using Threshold magic, I advise dramatically increasing the Recovery Rate (ideally above Threshold) and making the Calamity table less painful on the low end and incapable of affecting things other than the caster on the high end. The reasons being that Recovery Rate, not Threshold, determines how many spells a mage can cast per day, and 8 energy of spells per day is pathetically low. Having the Recovery Rate higher than Threshold encourages players to go over Threshold and actually engaging with the Calamity table, which is also helped by less painful calamities on the low end. On the high end, a mage shouldn't be able to turn himself into a suicide bomber by casting a ridiculously large spell, and limiting large calamities prevents that.

The last two threshold mage PCs in my games had Threshold 30, Recovery 45. One of them managed to trip 5-6 calamities before needing to stop spell casting for a week. I think his penalties at that point were double tally costs for 2 of his favorite spells, double tally casts for both of those spells' colleges, and a reduced Threshold and Recovery. It was quite exciting watching him push his luck well past the point of reason.