• A Thaum is the basic unit of magical strength. It has been universally established as the amount of magic needed to create one small white pigeon or three normal-sized billiard balls.

    Terry Pratchett: A Thaum is the basic unit of magical strength. It has been universally established as the amount of magic needed to create one small white pigeon or three normal-sized billiard balls.
    Terry Pratchett (2012). “The Wit and Wisdom of Discworld”, p.18, Harper Collins