It takes two free slots to start a brand-new skill, but it only takes one free slot to improve an existing skill.
Some skills offer bonuses to other skills (such as herbalism to chemistry).
A character can role-play learning a new skill (under the GM's direction). For example, a character may spend six months in game time as a blacksmith's apprentice to learn blacksmithing.
Certain magical books will convey new skills.
A Player Character can cash in a wish to learn a new skill.
Constructs can choose to either learn new skills or develop a new accessory.
Skills cannot be unlearned.
It is preferable to learn at least one "career" skill so that the Player Character has plausible employment in-between adventures.
Throughout the text, the terms "Skill" and "Proficiency" are used to describe the ability to wield weapons and complete skilled tasks. It should be known that "skill" and "proficiency" are interchangeable terms.