Dungeon difficulty is a setting that increases the challenge and rewards of a 5-man dungeon instance at maximum level. As of Battle for Azeroth, dungeon difficulty includes Normal, Heroic, Mythic and Mythic+, each with progressively increasing difficulty. These settings have gradually been made available throughout the history of World of Warcraft, with the latest addition of Mythic+ in Legion.
The Burning Crusade
The Burning Crusade has brought a new dungeon system which incorporates a dungeon difficulty setting. The simple concept of the dungeon difficulty spans across two levels. Firstly there is the normal setting, in which players will experience average loot as would be expected in any World of Warcraft 5-man dungeon. Heroic, however, is a little different.
Official Introduction
From Frank Pearce's Interview for the Official EU (en) site[1]
Q: Dungeon difficulty setting?
- A: The dungeon difficulty settings will allow you to replay dungeons at an increased level of challenge, meaning you'll also gain access to greater rewards. For example, you'll be able to replay that same level-63 wing you just mastered later on at level 70, with level-70 monsters and level-70 drops. If it's a level-70 wing and you play it at the harder difficulty level, the content will still be level 70, but the loot tables will reflect the higher challenge that comes as a result of the monsters having more hit points and dealing more damage. Or you might get more monsters per pull...that sort of thing. We are definitely trying to provide a great deal of content for players, regardless of the amount of time they have to devote to it or how many other people they like to play with.
The differences between Heroic and Normal
It should first be noted that heroic mode dungeons are not generally available for WoW Classic dungeons. However certain dungeons did receive them in later expansions: for example in the release of Cataclysm, Deadmines and Shadowfang Keep gained heroic settings.
In heroic dungeons, the enemies that you encounter will not just be of increased level, but also an increased difficulty far greater than their level would indicate. All enemies in heroic dungeons will be in the range of levels from the level cap to three levels above. However, heroic dungeons are substantially more difficult than the normal dungeons. Expect the trash mobs to hit well-geared plate tanks pretty hard for some particularly strong mobs. Also, expect bosses to hit harder, use their abilities more frequently, and often have new abilities.
Gaining access to heroic dungeons
To be able to access a heroic dungeon as a party, each member of the group must be at level 70. If all party members are level 70, the party leader can set the dungeon's difficulty to normal or heroic via menu options available by right-clicking his or her own portrait, or queuing via Dungeon Finder tool.
Rewards
Each boss drops a rare loot on par with or better than loot from normal level 70 dungeons.
End bosses are guaranteed to drop one epic item from their loot table in addition to a second, rare, item.[2] They also usually drop a 
[Primal Nether].
Wrath of the Lich King
Gaining access to heroic dungeons
In order to access Northrend's dungeons in heroic mode, each member of the group must reach the level 80.
Rewards
Each boss drops a rare loot on par with or better than loot from normal level 80 dungeons.
End bosses are guaranteed to drop one epic item from their loot table in addition to a second, rare, item. They also drop a 
[Frozen Orb].
Patch 3.2
Patch 3.2.0 brought the use of normal/heroic difficulty for 10 and 25-man raids in the Crusaders' Coliseum. Players will find new options when right clicking on their own portrait.
| Dungeons | Old | New |
|---|---|---|
| Dungeon Difficulty setting | Dungeon Difficulty setting | |
| 5 Player normal Dungeon | Normal | 5 Player |
| 5 Player heroic Dungeon | Heroic | 5 Player (Heroic) |
| Raids | Old | New |
| Dungeon Difficulty setting | Raid Difficulty setting | |
| 10 Player normal Raid | Normal | 10 Player |
| 25 Player normal Raid | Heroic | 25 Player |
| 10 Player heroic Raid | - | 10 Player (Heroic) |
| 25 Player heroic Raid | - | 25 Player (Heroic) |
Note: If a heroic raid mode is selected, the previous raids which did not use this new feature will be launched in the selected mode (10 or 25-man).
Patch 3.3
Patch 3.3.0 brought new changes to dungeon difficulty settings, which at the time were similar to raid difficulty settings.
- In the upcoming patch we are adding a new feature to the Icecrown raid instance that allows the raid leader to change the instance's difficulty setting on a boss per boss basis. The way the raid leader chooses to switch is the same as now, by right-clicking on the character portrait. The difficulty settings can be changed from inside Icecrown Citadel, with some restrictions. For example, you cannot change the difficulty in combat or during certain events specified by our design team. To enable the ability to change the raid difficulty to heroic, you must first defeat the Lich King on normal mode, as doing so unlocks the heroic version of this raid instance. There is no heroic version of trash; meaning changing the difficulty will only affect boss difficulty.
- We chose this particular functionality because we didn't want to use the Trial of the Crusader method, and have four versions on a raid of this size. We felt the Ulduar method of having to know a certain trick to do on the boss was difficult to communicate and tied too heavily to achievements. We might eventually convert Trial of the Crusader over to this new system but Ulduar and Naxxramas will likely never change.[3]
Cataclysm
Gaining access to heroic dungeons
In order to access Cataclysm's dungeons in heroic mode, each member of the group must reach level 85.
Rewards
Each Non-Zandalari Boss drops a rare item with Item Level 346. The End Bosses will drops two rare item with Item Level 346.
Each Zandalari Boss drops a epic item with Item Level 353. The End Bosses will drops two epic item with Item Level 353.
Justice and Valor Points
Whatever heroic dungeon you complete via Dungeon Finder(at your level) you will receive some extra reward other that Experience and Money.
Killing each Burning Crusade Heroic Bosses you will receive 5 Justice Points.
Completing Wrath of the Lich King Random Heroic you will receive 24 Justice Points and 16 each boss.
Completing Cataclysm Random Heroic you will receive 70 Valor Points, and 70 Justice Points each boss.
Completing Rise of the Zandalari Random Heroic you will receive 140 Valor Points, and 70 Justice Points each boss.
Later expansions
As with prior expansions, reaching the maximum level was required for accessing heroic dungeons.
Mists of Pandaria would introduce the Challenge Mode variant of Heroic Difficulty. It granted rewards other than gear, it lasted until Legion.
Mythic difficulty was introduced during Warlords of Draenor in patch 6.2.0 and was subsequently rolled out to all of the dungeons in the expansion. Mythic difficulty is above and beyond Heroic, and on Mythic, bosses' loot contained gear of a higher quality than heroic loot. This difficulty would become available to all subsequent dungeons in further expansions.
In Legion, Mythic+ was introduced, further increasing difficulty over Mythic, and adding random modifiers to dungeons. Unlike previous settings, a 
[Mythic Keystone] is required for each dungeon run.
In Shadowlands, 
[Valor] was reintroduced as a currency for upgrading gear acquired from Mythic+.
See also
- Dungeon difficulty
- Raid difficulty
- Legacy raids
- Related types