Attribute

Attributes are numerical values that represent a character's natural ability. There are three attributes in Path of Exile: Strength, Dexterity, and Intelligence. Each attribute has a colour associated with it for easy identification: Strength's colour is red, Dexterity's colour is green , and Intelligence's colour is blue.

Attributes are the most basic statistic, and has wide reaching effects on most parts of the game. All character classes, skills, support gems, item sockets, monsters, and many items have one or more attributes associated with them.

Classes
Each class has an affinity for one or two attributes, meaning they will find it easier to use the various skills and equipment aligned with that attribute. This has a cascading effect that impacts on all aspects of gameplay.

Acquisition
Each passive skill has one or more attributes associated with it. When a character invests in a passive skill, the character gains points in whatever attribute that skill is aligned with. Characters whos class attribute is the same as the skill's attribute will gain more points. For instance a Marauder will gain more strength than a Witch when investing in a strength based passive skill.

Equipment
Most armour and weaponry has one or more attribute requirements, that must be met in order to use the item. This requirement determines some of that item's statistics. A character must have an attribute score greater than or equal to the item's requirement(s) in order to use the item.

Armour
On armour pieces, the attribute requirements(s) affect the defensive benefit that the armour gives.
 * Armour with a strength requirement provides Armour
 * Armour with a dexterity requirement provides Evasion
 * Armour with an intelligence requirement provides Energy shield

Weapons
On weapons, the attribute requirements(s) affect some of the item's statistics.
 * Weapons with a strength requirement have higher base physical damage
 * Weapons with a dexterity requirement have higher attacks per second
 * Weapons with an intelligence requirement have a higher critical strike rating

Sockets
A piece of equipment is more likely to recieve sockets of a certain attribute if the item requires that attribute. For instance a sword with a high strength requirement is more likely to receive red (strength) sockets than sockets of other attributes.

Skill gems
In order to be used, skill gems must be placed in socket of the appropriate colour. As a result, characters will be more easily able to use skill gems of their class's main attribute(s).

Monsters
Like player characters, monsters also have attribute scores, which will affect them in many ways, such as their statistics (damage, evasion, etc.) and the types of skills they are likely to use.