The Stats tab of the Inventory window (I) displays the current attributes of the player. If you click on the Stat name, description will be presented to read in the window below the stat. The major stats are: Health, Power, Defense, Might, Restoration, Vitalization, Precision, Toughness and Dominance.
Toughness and Defense are stats that allow you to reduce damage. In order to defend yourself properly in PvP combat you have to build Toughness, Defense does nothing for you during PvP combat. Gear can have one but not both, thus one gear set for each enemy type.
Health (green bar) measures ability to withstand knockout. Health automatically begins to recover out of combat.
No Fighting Style provides any bonus to Power. Power (blue bar) is required to use powers in your Loadout, and is drained as they are preformed. Power builds during weapon attacks as shown by the hit counter; power also regens slowly out of combat.
Defense reduces damage from non-player enemies; the higher you level the more defense is required. Defense is included on all quest rewarded gear and weapons. It is mostly important to Tanks.
Stat Formula: 1% Damage Reduction = 15 Defense (level 1) and 71 Defense (level 30).
Might increases damage from powers.
Stat Formula: Adds .25% per point at level 1 up to .35% per point at level 30.
Restoration increases healing. The higher your Restoration, the more you heal. Obviously it is important for Healers, but it is also key to Fire Tanks who use self-heals.
Stat Formula: 4 restoration = 1% base healing increase.
Vitalization increases power healing effects. Vitalization affects your ability to restore the blue bar (Power). In DCUO, the ability to “heal power” is a Controller function, so Vitalization is mostly important to Controllers.
Stat Formula: 10 Vitalization = 1% power generation increase
Precision adds damage to all weapon attacks.
Stat Formula: 10 Precision = +1 DPS
Toughness reduces damage from player enemies. The higher your level, the more Toughness is required. Toughness is the primary PvP stat. It’s available from PvP gear bought from vendors. Certain safe houses have lower ranked PvP gear and the HQs have rank 30 PvP gear which requires special PvP currency as well as cash. The bonuses to Defense & Toughness provided by Fighting Styles always come together; any Style which buffs Defense also buffs Toughness by the same amount.
Stat Formula: 1% damage reduction = 15 Toughness (Level 1) and 71 Toughness (Level 30)
Dominance is a pure controller stat. It increases the number of health points lost by a target before a Control effect ends. At high levels, Dominance must be higher than enemy Willpower to be effective. Dominance increases duration/strength of stuns, encasements, roots, etc. Dominance definitely seems to effect knock-up/knock-back abilities. Various endgame Raids and Alerts have recommended Dominance levels. This is crucial when doing hard modes with medium difficulty and raids. As a controller if you go into a medium hard mode or raid with your dominance under the recommend amount ( 200 medium, 350 raid) your control spells will be out right resisted making you ineffective at cc.
I think that Willpower doesn’t exist on real player characters, it’s a stat given to NPCs to increase the relevance of gear for the Controller role. When I tried the daily solo missions they were very difficult because I couldn’t stun the bosses at all. When I improved my gear (~ 200 Dominance ) and tried them again I was able to stun bosses with no problem.
Stat Formula: 2 Dominance = 1 additional damage before control breaks.