The Elder Scrolls III: Morrowind · Magic skill group
Casting skills
Destruction, Restoration, Mysticism, Alteration, Conjuration, and Illusion govern the chance to cast spells from their respective schools.
How it works
Each listed school has a skill that determines the chance of successfully casting its spells. Successful casts raise the corresponding skill, and the Steam guide says experience gains occur in set amounts for casting any spell from that school, regardless of the spell’s chance or magnitude. The guide also describes spell success as affected by skill, cost, and fatigue.
Read the supporting references
The Elder Scrolls III: Morrowind/Skills Steam Community :: Guide :: The Arch-Mage's Handbook - A Practical Guide to Morrowind's Magic System
Check the edition and source version for patch-specific details. Guide methodology.