Most talent builds (also referred to as talent specs or talent specializations) are identified by the names of the talent trees, with the tree with the most points named first. A "disc/holy" priest has 31 points in the discipline tree and 20 in the holy tree. Usually no more than 51 points are put in a single tree, because that's the required number for reaching the highest talent. There are, or course, exceptions. The act of choosing such a path is referred to as speccing. Changing a character's spec is called respeccing or is referred to as a respec.
Starting at level 10, players receive one talent point for each level they attain. Players can spend these to enhance their character, making it better than a default, cookie-cutter example of their class. Often players will spend Talent Points in such a way to increase their enjoyment of playing their character's class, especially by enhancing abilities that they find themselves using often or to give new abilities that are useful in the style of play they enjoy most.
Often a spec defines the role a character will play in a group. For example, a Protection-spec warrior or paladin makes an ideal tank. A character's spec can radically shift this role. A Holy or Discipline priest will generally heal in an instance, while a Shadow-specced priest will DPS and crowd control. Certain talent trees excel in PvE content, while others are especially useful for PvP content.
It should be clear at all times that there is no "best" solution for anything in this game. The greatness of WoW is that there are many approaches to any goal. Just as there is no "best" race for each class, there is never a "best" build for each class. Everything is a tradeoff - an increase in efficiency in PvP usually means a decrease in PvE or endgame instances, and vice versa.
Of course there are certain basic truths, such as "a mage is a DPS class", "Hunters are good pullers", etc., which are widely accepted while some talents are considered "bread and butter skills". There are also simple and natural ways to achieve things — if you want to play your priest solo, it's much easier if you skill him as a Shadow priest. By no means should this be taken as "Disc/Holy priest cannot play solo" — of course he can, it's just more challenging.
Changing a character's talent build is called respeccing or is referred to as a respec. Characters can unlearn all of their talents (becoming untalented) at their respective class trainers, at a cost. Unlearning talents scales up the more times it is done: 1 gold, 5 gold, 10 gold, 15 gold, etc., up to 50 gold.
The cost to unlearn talents decays over time. This cost will be reduced by a rate of 5 gold per month to a minimum of 10 gold.
- Main article: Death knight builds
Death knights are World of Warcraft's first hero class. They are a hybrid class that combines damage dealing and tanking. Each talent tree for death knights can be used for either of those roles but depending which you choose will affect their play style. Blood focuses on the physical damage dealt by melee spell, weapons and abilities with a high self-healing rate and single target DPS. Frost focuses on control elements, with a strong critical-strike/bonus-damage, as well as several talents that improve damage mitigation. Unholy heavily focus on diseases, improving summoned minions, AoE, spell damage shielding and movement improvement abilities.
- Main article: Druid builds
Druids are a hybrid class that switch roles largely through shapeshifting. In their original humanoid form, they are similar to priests, able to damage their enemies with spells, buff themselves and their allies, and heal people. The restoration and balance trees enhance their healing and spell damage respectively. The cat form is geared toward stealth and melee DPS, while bear form allows them to tank. Those forms are enhanced by the Feral Combat tree, with a few special talents in restoration. Druids can acquire specialized forms for balance and restoration, but many non-raiding druids will stop short of Tree of Life Form to get extra versatility from balance or feral combat.
- Main article: Hunter builds
The hunter is a pure DPS class, known for their pets, long-range abilities with a gun or bow, and traps. Each of their talent trees focus on improving one of these aspects in some fashion. Depending on your playstyle, you may focus on one of these alone, or follow a hybrid build. Beast Mastery hunters are known to level extremely quickly and be effective in PvP, but produce sub-par damage output in raid. If you prefer to deal most of the damage by yourself, Marksmanship is your choice, with high, bursty physical damage. Survival Hunters excel at getting out of close range by more useful traps and more frequent stuns. Marksmanship and Survival both excel in a raid environment, and all three specs provide useful buffs to party and group members, including 3% damage, 10% Attack Power, and Replenishment.
- Main article: Mage builds
Mages are used as a ranged DPS class. In groups, they deal high amounts of damage to their targets, while generating a great deal of threat from monsters. They excel at doing Area-of-Effect damage (doing damage to multiple mobs at once). Mages have the greatest AoE capability of any class currently in the game. In addition, they are the weakest class at surviving having damage dealt against them. Because of this, it is advisable that another group member tanks while the mages do their thing. Mages have strong control mechanisms, such as snares, roots and crowd control. Frost mages enhance these control abilities, while fire mages specialize in sheer all-out DPS. The arcane tree remains a powerful utility tree providing strong burst DPS as well as very competent single target DPS.
- Main article: Paladin builds
The paladin class is based on surviving and keeping allies alive. In endgame instances, paladins can heal, tank or dps depending on their spec. A paladin comes loaded with defensive and offensive buffs, and invulnerability spells for himself and others. The talents he chooses will augment these skills in certain ways. The Holy tree increases healing and holy damage as well as making them more difficult to interrupt; it is a great PvE and PvP build. Protection is another way to keep your allies from dying, by taking the damage yourself as a tank. This spec is required to main tank five-man instances and epic-level raid content, and is on par with both warriors and druids in the tanking hierarchy. Retribution paladins are able to produce massive damage output. It is a paladin's best PvP spec. Since Patch 2.3, it has gained popularity in endgame PvE as well.
- Main article: Priest builds
Holy priests are famous for their various healing spells and the protective shield, which make them the favorite healers for many people. While the traditional role of a priest is healing, Shadow priests, who can dish out significant single-target DPS and provide mana regeneration for the whole party, are also a common sight for end-game raids. Shadow priests also do very well in PvP. The Discipline tree helps the mana threshold, thus it complements both Holy and Shadow. In addition to powerful healing and single-target damage, Priests can also supply players with helpful buffs.
- Main article: Rogue builds
A rogue's main purpose, either solo, in small groups, or in a raid, is maximum DPS, with crowd control as a secondary role. Assassination rogues are skilled at dealing massive burst damage from the back of the enemies using daggers. On the other hand, Combat Rogues are balanced with both offensive as well as defensive talents, and produce sustained damage using sword, mace or fist weapons. While the damage improvement provided by the Subtlety tree may not be as impressive as the other two, Subtlety Rogues can perform many subtle moves in PvP and easily catch their unwary enemies by surprise.
- Main article: Shaman builds
Shaman is a very versatile class. In endgame instances, their main roles are buffing and curing, as well as healing or DPS depending on spec. Restoration tree provides many wonderful abilities for those who would like to heal and support the others. Enhancement shamans focus on dealing physical damage. They are also loved by other melee DPS for the offensive buff their totems bring. In contrast, Elemental Shamans are caster DPS who usually do their damage from range. For PvP, Enhancement is a weak choice, because it needs melee range, but lacks ways to get or stay there. Restoration maybe preferred more. Elemental is better than Enhancement but vulnerable to interrupt/silence effects as all healing and most damage spells are of the nature school.
- Main article: Warlock builds
Although all the three trees can enhance the damage power of the warlocks, the playstyle of the warlocks of each specs can be very different. Affliction increases the power of the warlock's curses and damage over time spells. Demonology helps the endurance of the warlocks, by splitting damage taken with pets and better buffs from their pets, by either keeping it active or sacrificing it. Finally, Destruction allows for a mage-like style of playing by improving their direct damage spells. Warlocks are widely considered to be one of the best one-on-one PvP classes in the game.
- Main article: Warrior builds
In the endgame instances, the traditional job of a Warrior is to tank. Warriors have a variety of abilities that give them strong threat production and damage mitigation. Warriors' strength also scale very well with gear. Dual-wield Fury warriors are among the top damage dealers in the game. With the continuing addition of better gear, it is becoming more common to see warriors in raids whose sole purpose is to DPS. In solo and PvP play where aggro management is irrelevant, the warriors can produce even more fearsome damage. The Arms tree also provides many important talents that help the warriors in PvP.