Seals are self-affecting magic effects while Blessings, the other core class mechanic, can be cast on others and often have longer durations. Auras are an area-of-effect buff and the third core class feature that rounds out the Paladin's playing mechanics. Although other classes have persistent area-of-effect buffs such as a Shaman's totems or a Druid's 41-point talents, only Paladins have passive, permanent aura. Understanding and mastering the use of these three core features are key to playing the Paladin class.
Sealing your fate
The Seal system is the most distinctive feature of the Paladin class, more than Blessings or Auras. While other classes may have castable or area-of-effect buffs, no other class operates on a short dual-purpose self-buff that constantly needs to be refreshed or unleashed. There are five different baseline seals, one talent, and two faction-exclusive seals for a total of seven usable seals. Seal refreshment is one of the more active aspects of playing a Paladin.
The baseline seals are Seal of Light, which returns health; Seal of Wisdom, which returns mana; Seal of Righteousness, which is used primarily by Protection Paladins and Shockadins to deal damage; Seal of Justice, which can stun opponents; and Seal of the Crusader, which is used mainly for its judgement effect. Seal of Command is the only seal talent and is a staple for Retribution DPS and PvP; Seal of Blood is a Horde-only seal that is also used for Retribution DPS; and Seal of Vengeance is an Alliance-only seal that represents a Paladin's only damage-over-time debuff (as opposed to Consecration, which is applied over an area, rather than on a target).
Judgement of Light and Wisdom are what I would consider defensive seals and are extremely useful in raid situations and generate massive returns over time should the Paladin manage to keep it applied on the opponent. Because neither scale with spell damage and healing, they are less useful when soloing unless the Paladin is Protection specced where Reckoning can generate good returns. If there are enough Paladins in a raid, keeping either Light or Wisdom extends raid longevity and/or eases the strain on healing melee DPS. The returns on both these regenerative seals are felt over time, so are ideally used in long encounters as opposed to short ones (e.g. clearing raid trash). These seals are about endurance rather than making short work of opponents.
Then there are offensive seals. Seals are a Paladin's primary means of dealing damage coupled with auto-attack. Seal and Judgement of Righteousness scale with spell damage and are the seal of choice for most Paladin tanks and Shockadins. The higher a Paladin's spell damage, the more damage the seal deals and more threat it generates. It is one of the key spells that help Paladin tanks frontload a huge amount of threat from the get-go. Seal of Command is a Retribution Paladin's bread and butter and give high returns on weapon damage. The higher a weapon's top-end damage, the better Seal of Command scales. Ironically, it also scales from spell damage, which has been removed from Retribution Paladin itemization, which makes it only half as effective. It is used by Alliance Retribution Paladins and in PvP as it gives the highest burst damage potential of any seal.
Seal of Blood, on the other hand, gives the most consistent DPS and scales considerably well with current Retribution itemization. The health loss is perfectly synergistic with Spiritual Attunement, allowing for passive mana regeneration and doubles the value of raid heals. This gives Horde Paladins an edge in raid situations for DPS. Seal of Vengeance, unfortunately, suffers from unreliability as its DOT debuff is not automatically applied. Despite a proc rate of 20 PPM, Seal of Vengeance takes too long to build up and therefore doesn't frontload nearly as much threat as Seal of Righteousness.
Judgement of the Crusader is the most basic preparatory judgement and is used to substantially increase Paladin and -- with Improved Seal of the Crusader -- raid DPS. It is hardly ever used as a seal, except for helping in leveling weapon skill. Judgement of the Crusader is also key to a Retribution Paladin's DPS contribution as the talent improves it to confer a raid-wide 3% critical effect chance on spells and melee attacks. Every single DPS receiving a 3% crit buff against a target generates massive DPS returns. If the changes in Patch 2.4.2 push through, the 40% increase that the judgement seal (thanks, Heilig!) confers to Crusader Strike will be a substantial DPS boost to raiders, as well -- although how it will compete with Seal of Blood and Seal of Command for Retribution DPS remains to be seen.
Judgement of Justice is a utility spell that doesn't quite fit into the paradigm of damage dealing or regeneration. Rather, it is an interesting seal that's fairly useful in 5-man instances against mobs that tend to flee at low health. When judged, Seal of Justice prevents fleeing NPCs from aggroing more mobs. Used on players, it is one of the most useful and effective PvP seals by restricting movement to 100%. Because of the 100% restriction, which is normal running speed, it isn't considered a snare and cannot be countered by normal dispel effects that target snares and immobilizing effects. Used as a seal in PvP, particularly by healers who don't intend to deal damage, Seal of Justice can be an effective -- albeit unreliable at 4-5 PPM -- means to counter casters. Lucky procs can interrupt spellcasting and break escape.
Seals are integral to the Paladin play style, but it has one glaring design flaw: in order to keep a seal on an opponent, the Paladin must refresh it with a melee attack. This makes it unusable by most Holy or healing Paladins who optimally stay away from direct contact with enemies, whether in PvP or PvE. This is a major design error because it disables one major feature of the Paladin class for one of the most popular specs. Raids shouldn't be forced to bring a Retribution Paladin for Crusader Strike's seal refreshment aspect.
This means that a healing Paladin does not optimize his contribution and actually does not use one of the three key features of the Paladin class. Some might argue that Protection and Retribution Paladins don't use Holy Light and Flash of Light nearly half as much as Holy Paladins, but I personally feel there was some opportunity missed with the class design by necessitating melee attacks to refresh a Judgement. If they changed Judgement mechanic to refresh on any Paladin attack, this would allow Holy Paladins more utility with refreshing Judgements as well as add value to Holy Shock, which sees little use in raid situations.
Furthermore, because seals grant returns upon melee strikes, most healing Paladins cannot use them. While play style distinction is part and parcel of being a hybrid class, it would have been interesting to see how Blizzard could have mixed in the seal system as part of a healer's spell cycle. Seals are short-duration buffs that need to be unleashed as a Judgement most of the time in order to make full use of the spell. This is why their duration is so short. If Blizzard found a way to have caster Paladins (healers) utilize seals and not just judgements in raid situations, it would open up more utility and possibilities for the class. Next week, we'll explore blessings and auras and the synergies between all three key class features.