Active abilities are unlocked when you acquire Books of Knowledge, which can be found throughout the world.
You can assign four melee active abilities and four ranged active abilities for use during combat.
To assign an ability:
• Open the Abilities section of the in-game menu.
Once the ability has been assigned, you can use it in-game by holding down the Range or Melee buttons and pressing the button which you assigned the ability to.
Passive abilities are unlocked through the skill tree as you level up, and appear as larger icons.
Once you have unlocked a passive ability you do not need to assign it, and can use it straight away.
You can reset your passive abilities at any time to use the points elsewhere.
Let us know if you have any questions!