Attribute

Every profession has 4 or 5 attributes, one of them being the primary attribute of the profession. The primary attribute of a profession is only available if the respective profession is also the character's primary profession. For example: an Elementalist/Mesmer has Energy Storage and all other Elementalist and Mesmer Attributes except Fast Casting, while a Mesmer/Elementalist has Fast Casting and all other Mesmer and Elementalist Attributes except Energy Storage.

Rank
Attribute point cost for each rank.

Ranks are the measure of a character's development of a given attribute. Their values indicate how powerful a certain attribute's skills are. Additionally, ranks in weapon mastery attributes (including Beast Mastery) will increase the damage dealt by using the respective weapon type. See Damage Rating progression for details on how weapon mastery attribute ranks affect damage.

Attribute Points (AP) are used to increase an attribute's rank. Each rank costs more points than the previous rank, as detailed in the table to the right. Attribute points can raise an attribute to a maximum rank of 12.

Equipment and other effects can raise attributes beyond rank 12 to a game-enforced cap of 20.
 * Attribute runes grant +1, +2, or +3 ranks to a specific attribute.
 * All headgear armor gives +1 to a specific attribute.
 * A weapon upgrade of Mastery (for staffs and martial weapons) and the "Master of My Domain" inscription(for shields and focus items) grant a 10–20% chance of boosting the item's linked attribute by +1 whenever a skill is used.
 * This bonus doesn't actually increase the attribute's rank, however, it only modifies the variables (the "green numbers") of the skill being used. This is the only way to exceed the attribute cap of 20.
 * Because these upgrades only work for attributes that can be linked to an item, certain attributes cannot receive this bonus. These are Beast Mastery, Expertise, Leadership, and all non-weapon assassin and dervish attributes.
 * Rangers, Necromancers, Elementalists, and Ritualists have skills that can boost their attributes.
 * Expert's Dexterity provides +2 to Marksmanship in PvE and +1 in PvP
 * Trapper's Focus provides +0...2 to Wilderness Survival
 * Aura of the Lich provides +1 to Death Magic
 * Awaken the Blood provides +2 to Blood Magic and Curses
 * Double Dragon provides +0...2 to Fire Magic
 * Glyph of Elemental Power provides +2 to all elemental attributes
 * Ritual Lord provides +2...4 to all ritualist attributes

There are also several ways to increase attributes that are only available in PvE. The consumables allow all attributes to be raised to 20 in PvE.
 * Blessings of the gods provide +1 to specific attributes.
 * Elemental Lord provides +1 to all elemental attributes.
 * The PvE version of Masochism provides +2 to Death Magic and Soul Reaping.
 * Candy Corn, Golden Egg, Grail of Might, and Lunar Blessing each provide +1 to all attributes.

The maximum ranks attainable in PvP are as follows (not counting "of Mastery" or "Master of My Domain"):

Many players prefer to specialize in 2 or 3 attributes to make most effective use of limited skill slots and AP. For example, a monk dedicated to healing might decide to have 12 rank in both Healing Prayers and Divine Favor. This costs nearly all the character's AP, but allows for maximum effectiveness of skills linked to those attributes. However, because of the quickly diminishing returns of higher ranks, it is a viable strategy to diversify into 4 or more attributes if a build requires doing so.

Keep in mind that these limitations only apply to human players; NPCs can have their attributes at a higher level than the 12 rank limit without having to resort to runes or additional equipment.