The talent system is tiered. There are low-level talents you must buy and master before you can learn high-level talents. However, you can see all talents in a category, and see the paths leading to all talents. In addition, mousing over any talent tells you what the talent does and what requirements you must meet to learn it. Talents that are grayed out cannot be learned, either because you have no talent points to spend or because you do not have enough mastery of other talents. Talents do not have level limits.

Learning Talents

To learn a talent, mouse over the talent first and decide if it is right for you. Talents are difficult to unlearn, so you should be sure before you commit to one. You can visit a class trainer to unlearn your talents. It will cost money to unlearn your talents in an increasing amount until it reaches a high cap. This is to prevent players from changing their talents daily and devaluing the choices that must be made. Also keep in mind that you cannot learn every single talent, so you should make a choice about which talents or what category of talents you want to learn. When you decide on a talent, left-click on it to learn it. There is no confirmation of your pick.

Once you click on it, you buy it. If by purchasing the talent you open new avenues of talents, the newly unlocked talents will turn from gray to bright. All classes have talents that allow the player to customize their character. Talents can be applied in the following ways:
To improve a class' existing spells or abilities.
To alter the functionality of existing class spells or abilities.
To acquire new spells and abilities.
To improve class skills.