- Hardcore is a separate game mode in which characters have a single life: death is final. Upon death, a character can no longer be played and every item equipped or stored in inventory or stash can be lost.
- Prior to patch 1.13 it was necessary to complete Normal with at least one character to access Hardcore mode. This is no longer the case. Hardcore characters can be created by checking the Hardcore box when creating new characters.
- Permitting allied players to loot corpses allows them to recover items equipped, but those in inventory and stash cannot be recovered (so charms are always lost). Allies must be in the same game when permission is given and when character dies to loot corpse. Dead character also needs to remain in game until corpse has been looted, since corpse is removed upon leaving. Allies should also have enough room in their inventory and stash to store looted items.
- Although games cannot be created or joined with dead Hardcore characters, they can still post in the Battle.net chat room.
- There are separate Ladders for Classic Hardcore and Expansion Hardcore. Ladder rank of a dead character will be preserved as long as it is not deleted.
- Names of dead characters can be recycled by deleting them and creating new characters with the same name (although any Ladder rank of the dead character will be lost). If a player does not log in with a dead Hardcore character at least once every 90 days, it expires and can then be deleted by anybody else creating a new character with the same name.
- Different titles are awarded for completing each difficulty level, depending on game mode:
| Title
|
Classic
|
Expansion
|
| Normal
|
Nightmare
|
Hell
|
Normal
|
Nightmare
|
Hell
|
| Male
|
Count
|
Duke
|
King
|
Destroyer
|
Conqueror
|
Guardian
|
| Female
|
Countess
|
Duchess
|
Queen
|
Destroyer
|
Conqueror
|
Guardian
|
Reference
|