Functionality in Guild Wars refers to the effects unleashed by a skill, the prerequisites for those effects to be triggered, and the order in which those effects take place. In contrast, resource costs are not considered part of functionality.
This wiki labels a skill as having changed in functionality if any of the following is altered as a result of a game update: the order in which the effects triggered by the skill take place; damage types; changes in conditions dealt or effects triggered; target (types, amount, or area of effect); and frequency (e.g. whether effects are triggered once or several times).
This wiki does not consider a skill to have changed function if the only things to change are numerical values, e.g. changes in Adrenaline or Energy costs; amount of damage; Activation or Recharge times; Attribute lines; Skill types; or Range.
 List of skills and attributes that have undergone functionality changes
- ANet sometimes decides to change skill functionality if their effects are considered too weak or strong, even with a change in numbers. This can include skills that are usually only used in specialized farming builds in PvE, or skills that are usually only used in a single PvP format.
 See also