Aura skill button icons are golden. All Active skills except Attack, Throw, Unsummon and Sacrifice use Mana. Most Passive skills do not use Mana. The Mana cost and other information about a skill is shown, when you move the cursor over the skill icon. You receive one extra skill point to distribute each time your character reaches another level of experience.
Some quests give extra skill points for a reward.
These can only be used one time per difficulty level. Skill Points from Items Staves, Wands, Scepters and Class-specific items give from 1 to 3 extra skill points. You will receive the skill points only when you have the item or weapon equipped. These items will allow you to use skills that you have researched or spent a skill point. These bonus skill points do not allow you to advance down the skill tree unless you already have a point in that skill.