In Last Epoch, characters have an attribute or attributes that represent what they excel at. For example, Rogue’s core attribute is Dexterity, while it’s Intelligence for the Mage. Each of these core attributes has a small benefit per point:
Strength grants 4% Increased Armor per point and improves the skills that rely on raw strength.
Dexterity grants 4 Dodge Rating per point and improves the skills that rely on skillful handling of weapons.
Intelligence grants 2% Ward Retention per point and improves the skills that rely on carefully studied magic.
Attunement grants 2 Mana per point and improves the skills that rely on the innate magic inside you and your surroundings.
Vitality grants 6 Health and 1% Poison and Necrotic Resistance per point.
As seen in the descriptions of the attributes above, they often improve skills with different expertise, and in most cases skills of a certain class by default benefit from the same stat. In some cases, more than one attribute can also scale a skill, like Primalist’s Gathering Storm that benefits from both Strength and Attunement. You can see what attribute scales a skill by hovering to the skill, and more detailed effect by holding ALT.
There are also ways to modify skills, or your character to gain additional benefits from attributes by selecting skill points, passive points or wearing items with those types of effects.