Alter Aeon Online Help

Keywords are:  'mana manna magic cast power'

Mana is the way that magical power is counted.  Every spell that you cast
will drain your mana, and if you do not have enough mana to cast a spell,
you will be unable to.  Mana is the second number in the default prompt.

Like hitpoints, you will regenerate mana over time, and will regenerate
faster while asleep.

You will regenerate more mana as you increase the level of your magic
using classes.  Age also will affect how much mana regenerates per tick.
A very old character will regenerate mana faster, but will also
regenerate hitpoints more slowly.