An experience point (abbreviated EXP or XP) is a unit of measurement for character level advancement. Advancing to the next level requires a fixed amount of experience points which is determined by a formula.
In World of Warcraft, you generally only get XP from killing mobs and completing quests, but you can also get some from exploring.
This is based on the concept that as characters defeat stronger enemies, they gain combat experience that allows them to improve their skills. This system is adapted from D&D and is present in some form or another in almost all roleplaying games.
Mob XP
(This information does not appear to be correct. For the correct information see Formulas:Mob XP.)
When you kill a mob of a certain minimum level, you get XP. That minimum level depends on your current level. There is a formula to calculate that minimum level: take your level, add 1, divide by 5, and round up. If you get less than 5, erase that number and replace it with 5. The result is how many levels below you your minimum experience-yielding mob level is. In short,
MML = CL - max(ceil((CL + 1)/5), 5)
If you'd rather just look it up, here is a table listing the minimum mob level that yields experience for a given character level:
| Char Lvl | Min Mob Lvl | Char Lvl | Min Mob Lvl | Char Lvl | Min Mob Lvl | Char Lvl | Min Mob Lvl | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 21 | 16 | 41 | 32 | 61 | 49 | |||
| 2 | 1 | 22 | 17 | 42 | 33 | 62 | 50 | |||
| 3 | 1 | 23 | 18 | 43 | 34 | 63 | 51 | |||
| 4 | 1 | 24 | 19 | 44 | 35 | 64 | 51 | |||
| 5 | 1 | 25 | 19 | 45 | 35 | 65 | 52 | |||
| 6 | 2 | 26 | 20 | 46 | 36 | 66 | 53 | |||
| 7 | 2 | 27 | 21 | 47 | 37 | 67 | 54 | |||
| 8 | 3 | 28 | 22 | 48 | 38 | 68 | 55 | |||
| 9 | 4 | 29 | 23 | 49 | 39 | 69 | 55 | |||
| 10 | 5 | 30 | 23 | 50 | 39 | 70 | 56 | |||
| 11 | 6 | 31 | 24 | 51 | 40 | 71 | 56 | |||
| 12 | 7 | 32 | 25 | 52 | 41 | 72 | 57 | |||
| 13 | 8 | 33 | 26 | 53 | 42 | 73 | 58 | |||
| 14 | 9 | 34 | 27 | 54 | 43 | 74 | 58 | |||
| 15 | 10 | 35 | 27 | 55 | 43 | 75 | 59 | |||
| 16 | 11 | 36 | 28 | 56 | 44 | 76 | 60 | |||
| 17 | 12 | 37 | 29 | 57 | 45 | 77 | 61 | |||
| 18 | 13 | 38 | 31 | 58 | 46 | 78 | 62 | |||
| 19 | 14 | 39 | 31 | 59 | 47 | 79 | 63 | |||
| 20 | 15 | 40 | 31 | 60 | 48 | 80 | 63 |
Warlocks probably have to pay more attention to this than anyone else, because, even at level 70, they still have to kill green or better mobs to acquire a Soul Shard.
Quest XP
I pulled the formula for quest XP by studying the XP rewards provided for various quests and various levels on http://www.wowdbu.com.
Character_Level <= Quest_Level + 5 : Quest_XP = (100 %) or Full_Quest_XP Character_Level = Quest_Level + 6 : Quest_XP = ( 80 %) or ROUND(Full_Quest_XP * 0.8 / 5) * 5 Character_Level = Quest_Level + 7 : Quest_XP = ( 60 %) or ROUND(Full_Quest_XP * 0.6 / 5) * 5 Character_Level = Quest_Level + 8 : Quest_XP = ( 40 %) or ROUND(Full_Quest_XP * 0.4 / 5) * 5 Character_Level = Quest_Level + 9 : Quest_XP = ( 20 %) or ROUND(Full_Quest_XP * 0.2 / 5) * 5 Character_Level >= Quest_Level + 10 : Quest_XP = ( 10 %) or ROUND(Full_Quest_XP * 0.1 / 5) * 5
Some lower level quests (Quest_Level < 10) seem to give full XP only for Character_Level <= Quest_Level + 4, differing by 1 level with the table above.
For the table look at the DifficultyColors Page.
There is also a theory that all quests give the same xp regardless of color until they turn "grey". This was the topic of an article on Wowinsider.
This is not a theory. Since day one, Blizzard has awarded full xp for the completion of a quest of any colour except grey. See Wow-Europe. The level at which a quest becomes green is exactly the same as for mobs. With the wide availabilty of quest leveling mods and sites to record maximum quest xp, it is easy to quickly test this yourself.
In respect to current level, higher level quests do yield a larger relative xp gain. However, in the time it takes to do these harder quests it is possible to do several of the lower quests. Each to their own, but don't get confuse the absolute value of xp gained as a number with the relative xp gained as a percentage of current level requirements. My personal strategy is to avoid reds, miss most oranges and focus on a mix of yellow and greens. If you are meant to do them then you will find you have time later. If by then you have already moved on, there is plenty of shiny new quests in the next zone.
Also, bear in mind that by completing higher as opposed to lower level quests, you will reach a point where the questse below you are grey and their are no new quests to complete. All that's left is the grind...
Match the green and yellow quests and there is more than enough to see you questing all the way through the game.
XP To Level
(note: For exact information on the amount of XP needed per each level, see Formulas:XP To Level.)
The experience needed for a given level is specified by a formula that takes in to account several different factors. Up to level 10, it takes 8*CL kills of creatures of your same level to advance to the next level, where CL is your Current Level.
At level 11, the "difficulty reduction factor" added in patch 2.3.0 will kick in, thus reducing the XP needed to level. At level 30 the "difficulty factor" (from the original game release) will kick in, which increases the number of kills needed to level.
At level 60, the expected XP from killing a mob of your level increases drastically, as it is assumed that you will be killing mobs in Outland. This increases XP required to level. However at the same time, another reduction factor (active 60-70 only, added at the release of WotLK) goes into effect reducing the XP needed.
At level 70, the expected XP from killing a mob of your level increases drastically again, as it is assumed that you will be killing mobs in Northrend. The 60-70 XP reduction factor expires also, thus causing a large jump in the XP needed to level.
The total experience needed to reach level 60 is 3,379,400.
The total experience needed to level from 60 to 70 is 4,722,000.
The total experience needed to level from 70 to 80 is 15,965,800.
The grand total experience needed to level from 1 to 80 is 24,067,200.
Patch changes
Patch 3.2.0 (2009-08-04): Battleground experience has arrived!
- Players will now be awarded experience for completing objectives and actions that yield honor in Battlegrounds (honorable kills not included).
- Players who do not wish to gain experience through PvP can visit Behsten in Stormwind or Slahtz in Orgrimmar - both located near the Battlemasters in either city - and turn off all experience accumulation for the cost of 10
. - Disabling experience gains will prevent a player from gaining experience through any means available in the game.
- Players with experience gains turned off who compete in Battlegrounds will face off only against other players with experience gains turned off.
- Behsten and Slahtz can reinstate experience gains for players, for a 10
fee of course. Any experience that would've been accumulated if experience gains were enabled cannot be recovered.