Quests are a group of objectives and challenges given to the player in exchange for rewards. Many quests unlock content, such as access to new areas or unique quest rewards.
While most quests can be started at any time, many quests have requirements, such as a minimum level or other quests before they can be started. Certain quests also require a certain skill level to be completed (eg. gathering a certain resource).
NPCs that offer quests have a [ ! ] displayed above their name. Monsters that need to be killed for a currently active quest will have a [ ? ] displayed above their name.
The In-Game Quest Menu can be accessed by pressing Q or clicking ? icon in the bottom right of screen. Right-Clicking on Active Quests in the Quest Menu allows for Quest Tracking, which displays current quest task on the screen and highlights quest NPCs and Monsters.
The seven + icons at the bottom of the Quest Log window each open different quest dialogs.
Current Task (if multi-step task will only show current task).
Last Speech (most recent dialog with quest-giver).
Quest Status. Also, provides option to Cancel Quest (See below)
Main Task. (if multi-step task will only show main task).
FAQ: How do I cancel a quest/Slayer task?
Click the quest you want to cancel to highlight it, click the third '+' from the left to show Quest Status, then click Cancel Quest!