Spellcasting is the basic skill for magic use, and affects your 
reserves of magical energy (MP) in the same way that Fighting affects 
your hit points. Every time you increase the spellcasting skill you gain
some magic points and spell levels. Spellcasting is a very difficult 
skill to learn, and requires a large amount of practice and experience.

Spellcasting is the basic skill for magic use. It affects your reserves 
of magical energy (Magic) in the same way that Fighting affects your hit
points: every time you increase the spellcasting skill you gain some 
magic points and spell levels. This skills greatly influences the amount
by which casting causes hunger. Spellcasting also helps with the power 
of your spells, but to a lesser extent than the more specialised magical
skills. This skill is very difficult to learn, and requires a large 
amount of practice and experience.