Using Judgement is typically referred to as "Judging" a target. Judging a Seal a Paladin has cast on himself can result in a myriad of abilities, from damage to utility debuffs. If the Judgement is a debuff, the duration of it can be refreshed each time the Judging Paladin lands a melee hit.
Rank
Level
Mana Cost
Cost
1
4
5% of Base
1
Talents directly improving Judgement
The Retribution tier 1 talent [Benediction] reduces the cost of Judgement and Seals by 3%/6%/9%/12%/15%.
You can decrease the cooldown by 2 seconds of Judgement with [Improved Judgement] (2 ranks, 1 second per rank) in the Retribution Tree.
[Sanctified Judgement] (3 ranks) gives a 33%/66%/100% chance of receiving 50% of the mana back of the judged seal.
The Retribution tier 8 talent [Fanaticism] increases the critical strike chance of any Judgement that is capable of critical hits by 3%/6%/9%/12%/15%; this would include Righteousness, Command, Vengeance(?) and Blood.
The Retribution tier 2 talent [Improved Seal of the Crusader] increases the critical strike chance of all attacks and spells made against a target affected by Judgement of the Crusader by 1%/2%/3%.
The Holy tier 2 talent [Improved Seal of Righteousness] increases the damage of Seal and Judgement of Righteousness by 3%/6%/9%/12%/15%.
The Retribution tier 3 talent [Seal of Command] is a more damaging Judgement than Righteousness and deals double damage if the target is stunned or incapacitated.
Judgement deals Holy damage to enemy, harming the Paladin for 33% of damage dealt.
melee / melee
Related Equipment
The Tier 2 Paladin armor set is called Judgement Armor and includes an 8-piece set bonus that inflicts 60-66 additional Holy damage to the target a Paladin is Judging.
The set also offers a distinct and fitting look for Paladins and many Paladin-centric armor pieces in the Burning Crusade expansion have used variations of the Judgement set, normally a different color theme.
[Improved Judgement], 
[Sanctified Judgement]
[Benediction] reduces the cost of Judgement and Seals by 3%/6%/9%/12%/15%.
[Fanaticism] increases the critical strike chance of any Judgement that is capable of critical hits by 3%/6%/9%/12%/15%; this would include Righteousness, Command, Vengeance(?) and Blood.
