how we use the crystals>?

[Roman]

Before you can learn a spell (by spending crystals) you need to have the appropriate skill - Chaos, Order or Distortion magic! And if you want to upgrade the spell to a higher level, you need to have the given skill at a higher level too.

[Sherwood]

Open your spell book tab... scrolls and spells will have an icon you can click on by the right side of their picture which allows you to either learn a spell (if its only a scroll)... or increase its level if you have already learned the spell and have the appropriate skills.

All spells have 3 level... and you need the corresponding magic skill to learn a spell.

So to learn fireball 1... you need destruction magic 1 and a scroll of fireball, to learn resurrection 2, you need to have already learned resurrection 1 and have order magic 2.

I hope that helps, as I don't think I can explain it with words with any more depth.