My house rules for magic which are working very well so far.
Magic:
Magic Skill ranks may not exceed Knowledge ranks.
Casting a spell or summoning a spirit costs 2 drain and costs no strain.
Drain differs from strain in that while it still draws from the same resource pool, Drain counts upwards from zero, and strain counts downwards from your maximum strain threshold.
Should your drain ever exceed your current strain, you fall unconscious.
Drain can only be healed by a long rest or at a rate of 1 drain per hour rested.
Example: Wizzo the mage is at current strain of 7/12 and has cast 3 spells for a total of 6 drain, should he cast one more spell before healing any strain, his drain would increase to 8, which exceeds his current strain therefore he falls unconscious.
Difficulty dice is considered Force of the spell.
Casting a spell that exceed the number of difficulty dice over the casters magic skill shall be X wounds as well as the 2 drain cost. X being the difference between force and magic skill. Wounds like this can be healed by normal means but not magical means.
Spirit summoning:
Both Hermetic mages and Shamans may summon spirit. But on shamans may use the full conjuring magic spell type. (Consider Summon spirits its own unique spell type)
The basic spirits in adversary section are considered Force 1 and cost 2 difficulty dice to summon.
To summon a higher rank spirit add the addition number difficulty dice as the spirit force difference to force 1. Add the same number to all characteristics of the summoned spirit.
I.e. Force 3 spirit increases the difficulty of the summon by 2 steps to 4 difficulty dice, however should the shaman succeed the spirit would have +2 to all characteristics.
