Quoting Labtec_au, reply 1Essence also determines the Mana level for casting spells
How do you generate mana?
I'm stuck at 0 of 100.
Mana is based on essence, mana will regenerate only if you still have essence, spend all your essence and you're out of luck (until you level up and buy more of it). If you do have essence, keep in mind that mana can take a while to regenerate, sometimes several turns to get back what you spend on a single spell. I think wisdom and intelligence affect mana as well - they give more regeneration or more mana per essence or something like that? - but the bottom line is 0 essence = stuck at 0 mana.