AdventureQuest Worlds now has STATS! To see a complete breakdown of stats and what they do, click on your Character Panel. How these stats affect your character depends on what Class you are currently using, what Rank your Class is, and what Enhancements (if any) you have applied to your character. Warriors benefit more from strength then a Mage will, and likewise a Mage will benefit more from intellect then a Warrior. Your Class Overview panel will outline some of this information for you. Experiment around with different stats and different classes to find a build that best works for your character.
Strength: Increases Attack Power which boosts physical damage. It also improves critical strike chance for melee classes.
Intellect: Increases Magic Power which boosts magical damage. It also improves critical strike chance for caster classes.
Endurance: Directly contributes to your total Hit Points. While very useful for all classes, some abilities work best with very high or very low total Hit Points.
Dexterity: Valuable to melee-based classes, it increases haste, hit chance, and evasion chance. Dexterity only increases evasion chance for caster classes, however.
Wisdom: Valuable to caster classes, it increases hit chance, crit chance, and evasion chance. Wisdom only increases evasion chance for melee classes.
Luck: Increases the critical strike modifier for all classes directly and may have some effects outside of combat. It is called Luck for a reason!