Talent tree mastery and effective talent level

Each tree has a mastery value. This value is a multiplier value to calculate the effective talent level. The formula is:

Effective talent level = Raw talent level * Tree mastery

Raw talent level is the number of talent points invested in that talent.

For example, with a raw talent level of 4 and mastery of 1.3 you will have the effective talent level of:

4 * 1.3 = 5.2

Talent abilities that are unlocked by having a higher level of the talent use the effective talent level for calculation.  Thus with a mastery of 1.3, level 4 of the talent will unlock level 5 abilities.

The mastery value can be improved by spending a category point to improve the tree or by wearing equipment that affects it.  Each category point spent will increase the mastery by 0.2.