From the back cover:
Feel the crackling flow of Essence course through you as you repel the soul-tearing power of a dark cleric! Stand firm against the insidious power of the mentalist, and loose the ravening elemental force of nature and void against your foes! Cast your lot with the best spell system around -- Spell Law!
Spell Law is the highly acclaimed magic system that improves any game! Now revised, reformatted, and reorganized, this is a mighty tome that can add realism and depth to your campaign without sacrificing playability. A must for your favorite characters, be they Magicians, Clerics, or Mentalists!
Spell Law provides:
Over 2,000 spell descriptions on 183 different spell lists based upon three realms of power and 18 professions.
Critical strike tables for Heat, Cold, Impact, Electricity, and spells against Large and Super Large Creatures.
Tables for resistance rolls, basic spell attacks, and expanded spell failures.
Optional rules providing further depth and detail for a campaign.
Extensive guidelines for using these tables with other FRP games.