When you gain a level, you’ll receive points to spend in the following:
Stat Allocation Example
As a Barbarian, each point of Strength will increase the damage of your skills, while Willpower improves Fury generation, and Dexterity grants critical chance. Meanwhile, as a Sorceress, Intelligence increases skill damage, Willpower grants critical chance, and Dexterity hastens mana recovery. Each stat also confers a secondary defensive bonus.
And here’s where it gets really interesting. Many of the nodes in each class skill tree have additional effects if you meet specific primary stat thresholds. You’ll get the baseline effect of these nodes when you spend the skill points to unlock them, but get enough of the corresponding primary stat and the bonus effect will activate.
Players also assign skill points. Example below is from December 2020.