Whenever a quest is initiated or changes status, Quest Log icon appears in bottom left corner of screen. Quest log can be opened on left half of screen by clicking on this icon or the Quest Log icon on pop-up panel above status bar at bottom of screen, or by pressing key assigned to Quest Log (Q by default). Clicking speech bubble icon in bottom right corner of Quest Log will normally replay speech of person to initiate quest while it is active.
The following quests normally need to be completed in Single Player or when playing without help in Multiplayer in order to progress to later Acts and difficulty levels:
- Khalim's Will is not mandatory in Multiplayer if player character completes The Blackened Temple, allowing use of Town Portal cast in Durance of Hate by an allied player who has already completed Khalim's Will.
The following quests do not normally need to be completed in Single Player or when playing without help in Multiplayer in order to progress to later Acts and difficulty levels, but are worth completing for their rewards:
- Value of rewards is subjective: these quests are recommended for player characters who are just starting or otherwise poorly equipped, but may be optional for more established and better equipped characters.
The following quests do not normally need to be completed in Single Player or when playing without help in Multiplayer in order to progress to later Acts and difficulty levels, and are not worth completing for their rewards:
- The Blackened Temple becomes mandatory in Multiplayer if player completes it instead of Khalim's Will, allowing use of Town Portal cast in Durance of Hate by an allied player who has already completed Khalim's Will.
- Players cannot use Town Portal cast by allied player if destination is area which cannot normally be accessed without completing these quests.
- The Summoner and Betrayal of Harrogath are mandatory for the Pandemonium Event.
The following are not displayed in Quest Log and are entirely separate from storyline, but they have been introduced at various points in the game's history for additional fun and challenge:
Quests can be initiated in a number of ways: talk to a townsperson, enter a quest area, find a quest item or approach a quest objective. Once initialised, quest status and any relevant items in inventory or stash are saved; they are also saved upon exiting game.
Talking to a townsperson with a speech bubble containing an exclamation mark above head may initiate a quest.
Townspeople will comment on active quests when character talks to them, and comments change as quest status changes (usually after initiation, return without completion and upon final completion). However, unless townsperson is actively involved in quest, what is said is normally for flavor rather than being of any practical use.
Objectives normally involve finding and killing particular monsters (normally Super Unique or boss) or finding quest items. Consult Quest Log at any time for reminders of what needs to be done for any active quests.
- In Multiplayer, quest cannot be completed if game creator has already done so: consult Quest Log to see what is available. Quests also cannot be completed if another player who is not an ally completes them in that game: notification is given when this occurs.
- In Multiplayer it is not necessary for each player to complete quest themselves as long as an allied player does so while they are present in the same Act, or within 53 1/3 yard radius (approximately 2 800x600 screen widths) of a quest kill. For example, only one player needs to complete Horadric Staff to allow allies to access Tal Rasha's Chamber.
- Once completed, quests cannot be repeated in that difficulty level (with the exception of World Event and Pandemonium Event).
Quest areas are areas in which character needs to perform an action in order to complete an objective. Entering a quest area will often initiate a quest. Character often needs to travel through multiple areas to reach quest areas, so navigation notes are normally made on individual quest pages.
Items often need to be found and manipulated to complete an objective, or may be found as a result of completing such an objective.
- Only items found in the same difficulty level can be used to complete quest; an exception is the Horadric Cube, which can be used regardless of where it was found or where it is used.
- Only one of each quest item can normally be picked up by the same character, with the exception of those dropped in the Pandemonium Event.
- Once they have served their purpose, quest items are normally removed from inventory.
If reward is not apparent upon completion of quest, consult Quest Log: normally character will need to talk to townsperson to claim reward. Aside from progress to later Acts and difficulty levels, notable rewards include the following:
- Cleansing the Den of Evil also allows character to re-specialise, resetting all stat and skill points.
- Ensure there is sufficient inventory space for items, otherwise they will drop on ground.
- Rewards can only be claimed by a character once per difficulty level, and they are not normally transferable between characters: for example, Scroll of Resistance granting +10 All Resistances cannot be transferred from one character to another when the recipient has already picked up or used their own.