Talent

Talents allow you to make a character better at performing certain actions. Most talents provide a passive bonus to your abilities, some talents grant new abilities and others provide situational buffs. This allows you to customize your character and stand apart from other characters of the same class. Talents are class specific and each class has three talent trees to choose talents from.

Gaining Talent Points
Characters need talent points in order to purchase talents. The first talent point is gained at level 10 (the same time you can choose a specialization). The second talent point is gained at level 11 and from then on a character will gain a talent point every odd level. Starting with level 81, characters gain a talent point every level.

Death knights are an exception: they start at level 55 without talent points, and must gain their first talent points as quest rewards.

Talent Point totals:
 * Level 60: 26 points
 * Level 70: 31 points
 * Level 80: 36 points
 * Level 85: 41 points

Choosing Talents
The talent menu can be accessed by clicking on the Talent icon on the interface bar at the bottom of the screen (assuming you are using the default UI). This pops up the Talent interface which features the main Talent window showing the tree and Talents. You can also activate the Talent interface by pressing the N key (if you haven't unbound it or bound the key to a different action).

When a character with no specialization opens the talent menu, it will show a summary of each specialization the class has. Once a specialization is chosen, the actual talent trees will be shown. You may switch between viewing the specialization summary and talent trees by clicking the button at the lower right of the menu.

Talents and Specialization
Before choosing any talents, a character must choose a specialization. Specialization is chosen at level 10 and the first talent point is gained at the same time. Characters must spend 31 points in their chosen specialization before they are allowed to spend talent points in any other talent tree.

Pre-Requisites
There are two restrictions on how you can spend your talent points. These are:
 * Specialization: Characters must spent 31 points in their chosen specialization before they can spend talent points in any other talent tree.
 * Tiers: Each row of talents on the talent tree represents a different tier. Each tier of talents requires 5 more points to be spent in that tree before they can be chosen. Talents on the second row require 5 points, third row 10 points and so on. The talent at the very bottom of the tree requires 30 points to be spent in that tree before it can be chosen. This final talent is usually exceptionally powerful and defines the playstyle of the class.

This means that the final 31 point talent in a character's specialization can only be chosen at level 70. At level 85, a character has enough talent points to spend 5 points in 2nd tier talents of a 2nd talent tree. It is impossible for a character to access tier 3 talents in a second talent tree.

Relearning Talents
Talents can be reset at any applicable class trainer. Relearning talents costs a fixed amount of gold based on character level.

If a character has dual spec, relearning talents resets all talent points and clears the specialization of the current spec.

Patch changes and talent resets
Occasionally, Blizzard will restructure a class's talent tree. If the change is significant, they may reset that class's tree, allowing you to respec for free. Talent changes do not always give a free respec: for example, in patch 2.3.2, the mage spell Ice Block was made trainable, and the talent Cold Snap was moved to its place, and the new spell Icy Veins was put in Cold Snap's old spot. This change did not give mages a free respec, but it required those mages specced for Ice Block to go to a trainer and buy that spell.

Prior to every Expansion, Blizzard has and will reset the talent tree incase the player wished to change before the new expansion.

Talent calculator
This tool allows you to plan your talent build. Wowhead Talent Calculator

Pet talent points
In patch 3.0.2, hunter pets went from having to be taught abilities using training points to having a talent tree, depending on the beasts' family type. Unlike players the pets start earning talent points at level 20 and then gain a point every 4 levels. So by the time your hunter reaches level 80, the pet will have 16 spendable points, unless the hunter has the Beast Mastery talent, which adds 4 more points.

Planning Talent Builds
While planning one's talent build, take note that Talents further down a tree tend to offer greater bonuses. It is particularly reccomended to take the "31-point" Talent found at the bottom of the tree, as this is intended to be the most powerful talent that is uniquely available to each specialization.

Characters may spend a maximum of 10 talent points in a talent tree other than the characters specialization. These talents often offer some synergy with the character's actual specialization and should be seriously considered.

Additional tips:
 * Consider allocating talent points in a manner that emphasises a particular role and style of play. For example, many talents are oriented for tanking, damage or healing roles.  Some are also oriented well for PvP or PvE.
 * If you intend to participate in end-game PvE raid content, it is reccomended to allocate talent points (and select gear) with the boss encounter in mind. For example, a talent that improves damage or survivability against the boss might be preferred over a talent that only improves damage or survivability against trash mobs.  The raid will undoubtedly find the boss encounter more difficult, and preparing for it will aid in surpassing the challenge.
 * This does NOT mean you should necessarily put all your points in one tree. Once you get the "ultimate talent" at 31 points, look at your other trees. Consider this a very strong, well-founded suggestion as the base talents in many trees work well with the advanced talents in other trees. That's not to say, however, that a Mage who puts all 37 points into Frost is automatically an easy target in PvP. In the hands of a skilled player, a 37-point single tree build can be very effective.
 * The following indicators can be used to distinguish between talents that are intended for PvE or PvP. Note that some talents cleverly offer two different bonuses, one for each type of play.  As such, these indicators are not necessarily the rule:
 * Any ability that activates "whenever you are critically hit" is a PvP talent (PvE players won't get critically hit much) and can be safely skipped if you aren't doing much PvP.
 * Any ability that gradually applies several stacks of a buff or debuff is designed for boss fights, which last long enough for these abilities to reach a full stack. When you're leveling, your fights usually won't last long enough, so skip these talents if there's something better available. However, these talents are extremely useful in PvE end-game raiding (during the boss encounter).
 * Any talent that decreases threat caused by your abilities is obviously a PvE talent, designed for group situations such as instances. They are not recommended whatsoever for PvP play, and are completely unnecessary in that area. These talents are also counter-productive for players wishing to fill a tanking role.  They are strictly for the PvE instance/raiding damage role only.
 * Any talent that makes you go faster in terms of movement (or mount) speed will save you a tremendous amount of time and is almost always worth getting while leveling, but may be considered less valuable during end-game raiding or arena play.
 * When leveling on a PvP realm, it is entirely understandable if you choose to create a versatile spec that allows you to perform decently enough in PvE but also gives you a boost in PvP capability in cases where you have to defend yourself from players of the opposing faction. In this case, this is a healthy alternative to focusing your talent build entirely on PvE or PvP.
 * After purchasing Dual Talent Specialization, many players will opt to have one PvE end-game raiding build and one PvP build.
 * There's no such thing as a bad spec (except in very few cases). That's still no excuse to bring your PvP spec into an end-game raid, however. Please be aware of the strengths (and purpose) of your talent build, and utilize them accordingly.
 * If you see someone else saying that only certain talent builds are acceptable, pay no attention to him/her. Talents were implemented so that players could further customize their characters. Five Mages from the same guild having the exact same talent build because they were told to is not customization. Choose the talents that work best with your play-style, but do be mindful of which talents you end up choosing. Again, choose the talents that work best with your play-style and you will become stronger.
 * If you're having problems being accepted due to your talent build (which shouldn't happen, but sometimes it can), purchase Dual Talent Specialization. Now you can have both a cookie-cutter build and your own customized build, and you can switch between them any time you wish. Problem solved!

Cataclysm changes
The Talent system underwent a large overhaul for Patch 4.0.1. It was at this time that Specialization was introduced and the number of talents were reduced. The following quote from Blizzard employee Zarhym describes the intent of these changes.