Manipulates the arcane world in ways traditionally associated with sorcery. You might call forth the souls of victims a soldier has killed and send them after him, or create a window in space to observe distant lands. – Illwinter.

Thaumaturgy is a small school, but its mind-affecting spells can be extremely powerful, particularly for astral mages.

The critical spells Communion Master and Communion Slave allow astral mages to form communions. The line of astral attack spells in Thaumaturgy – Mind Burn, Paralyze, Soul Slay, Enslave Mind – are unique in that they ignore distance and precision, and a group of astral mages casting them can be a potent force.

Besides these, Thaumaturgy is mostly utility spells. There are scrying spells (Scrying Pool and Astral Window), some site-search spells (Haruspex, Auspex, Gnome Lore, Augury), some very powerful but situational anti-undead spells (Dust to Dust, Wither Bones), magic phase movement (Teleport, Gateway, Astral Travel), and a few very powerful global enchantments (Burden of Time, Vengeful Waters, Gale Gate, Dark Skies).

Thaumaturgy is most famous in the late game as the school of Master Enslave, which allows a single very powerful caster or a communion with a large amount of penetration-boosting equipment to devastate an army.

• Fire lets you sow Chaos and blind Rage.
• Air lets you Steal Breath and sow Confusion. Air's Gem Generator is in this school, too.
• Water lets you simulate both Dehydration (Desiccation) and Drowning (Sailors' Death). It also lets you Scry.
• Earth lets you give and take Willpower with Iron Will and Melancholia (respectively).
• Astral lets you control Space, and the Minds (and possibly the Souls) of others. It's the big one for this school.
• Death lets you sow Terror, Aging, and Plague, and also lets you check (counter) the Undead. It's another biggie.
• Nature lets you control Passions, Senses, Sensibilities, Immune Systems, and Sleep. It's a third biggie.

On top of that, it has the Site-Searching Rituals for Fire, Air, Earth, and Nature.