Commander Upgrades fall into two categories: Attributes and Proficiencies. Attributes are the commander's method of increasing their stats directly. Proficiencies are used to tune the commander's role on the battlefield.
Each Attribute starts off with a hard cap limiting the number of points that can be placed into it. This cap varies by commander. Points are earned with experience. Every 5 Attribute points earned grants 1 Proficieny point.
- Weapon Damage -- Directly increases the commanders damage per hit of auto-attacks and increases the effects of certain Abilities.
- Attack Speed -- Reduces the time between auto-attacks.
- Health -- Increases the commander's max health.
- Armor -- Increases the commander's damage reduction.
- Power -- Augments the commander's maximum energy ("mana") and increases the the effects of certain Abilities.
- Cooldown Reduction -- Reduces the cooldown timer of all the commander's Abilities.
Proficiencies are sub-divided into seven groups, each group generally dealing with one or two of the six Attributes and a seventh utility group.
A complete list of the Proficienies can be found here