Rank

Rank is the designation of a skill's efficiency and improvement.

All skills are acquired at rank 0, their base level. As the rank increases, costs of the skill decrease and effects increase.

Ranks can be improved in two ways:

1. Gear can provide a rank bonus, increasing the rank of a skill. Having a rank bonus does not improve a skill you do not possess.
2. New Milestones in a Profession that shares at least one element of the skill's Skill sphere allows one to raise the rank of one skill by 1. It is impossible to raise the rank of a skill twice using the same Milestones.

Changing active Professions cause any rank-0 skill that cannot be improved by the new Profession (that is, lacks any common element with its Skill sphere) to be lost. They can be re-learned with a new active Profession later, but they cannot be used.

Adaptation

The Adjustment of the Labyrinth provides no rank increases with its Milestones, presumably because it is not a true Profession and lacks a Skill sphere.

However, the presence of Adjustment allows one to acquire a new rank-0 skill by merely equipping a piece of gear with it, provided it is in the same Skill sphere of the current active Profession. Doing so bypasses any tier "restrictions".