Basic unit of magickal energy, a thaum provides enough force to perform a simple cantrip or orison.
This unit of measurement, instituted by Numismatos, First Mage of Celestia and founder of the Arcanum in 1587 CR, is the principle upon which Celestine operates and the method by which new spells are developed.
The Arcanum uses the following system to determine how much thaumic force is found in a given magickal effect:
- 1 thaum: create a minor magical effect such as light a candle, flavor food, or clean 1 cubic foot of material
- 10 thaums: create an instantaneous burst of flame to cover a 10’ cube
- 100 thaums: summon a sustainable 40’ long and 10’ high wall of flames
- 500 thaums: call down meteors from the sky; construct a Godchain
- 1000 thaums: blight an inland sea; construct a Skyship
- 10,000 thaums: murder an army; raise a mountain from bare earth
The Arcanum also notes that blood sacrifice has also been known to generate thaumic energy.