Quests are typically grouped into one of four categories: kill quests, gather quests, delivery quests, and escort quests. However, quests can include more than one mission, such as gathering something and transporting it somewhere. Quests can be linked together to form quest series or chains. In this manner, quests are used to provide the player with further background to the setting their characters are in. This mechanism is also used to advance any story or plot the game might have.
Many types of quests are referred to as "sidequests". These are specifically tasks which deviate from the main plot, and are often not required to complete the game. Examples include minigames and running errands.
In the most general sense, a quest is a "hunt for a specific outcome", in contrast to simply winning a game. Typical quests involve killing a set number of creatures or collecting a list of specific items. Some quests may take only a few minutes or hours to complete, while others may take several days or weeks. Often, the larger the reward, the longer the quest takes to finish, and it is common for a quest to require characters to have met a certain set of pre-conditions before they are allowed to begin.
Questing is a tool used in role-playing games to avoid putting players in a position where they only perform a repetitive action, such as killing creatures. Players may be performing this activity in order to gain new skills and progress to new areas, or to gain in-game money in order to buy new items, such as armor and equipment. This process, commonly known as "grinding", can slow down a character's progression in the game and ultimately limit the player's enjoyment. Having a number of quests for characters to tackle is seen as a way to provide variety, and to counter the need to grind in these types of games.
A sidequest is an optional section of a video game, and is commonly found in role-playing video game. It is a smaller mission within a larger storyline, and can be used as a means to provide non-linear structures to an otherwise linear plot. As a general rule, the completion of sidequests is not essential for the game to be finished, but can bring various benefits to the player characters.