Magic

From Elona Wiki

In order to use magic, you must first learn spells from magical spellbooks.

When you successfully finish reading a spellbook, your stock of magic in that spell increases. Every time you cast a spell, the stock decreases by a semi-random amount detemined most likely by the spell level the caster has in that spell. In general, spells that casters have low levels in will use as much spell stock as mana when casting a spell while spells that the caster has high levels in will use much less. Casters have to (re-)read books to get more stock in a spell if they run out.

Casting spells will tend to have positive effects on the stats that govern them (eg: will, constitution, magic).

As your magic stat improves, your spells will have extra dice added to their rolls. For instance, Magic Dart level 16 went from 3d13 to 4d13 at MAG 49->50, and nerve eye level 1 gained a die at 35->36 MAG. Spells which are harder to learn seem to benefit more from this (at 100 MAG, Magic Dart 16 did 5d13 and Nerve Eye 1 did 6d11, and at 173 MAG Nerve Eye was 10d11 and Magic Dart still only 6d13).

Additionally, the magic stat influences the amount of MP you can have.