A typical quest will announce that the heroes must assemble some artifact, which unfortunately for them has been broken into several pieces, each of which is guarded by terrible threats which the heroes must overcome. The quest allows the heroes to shine and show the qualities that make them heroic.
Perhaps the original quest motif is the quest of Gilgamesh, who goes out in search of the secrets of eternal life. Another ancient quest tale is the story of Odysseus, who finds many dangers between him and his goal, which is simply to return home. This quest tale was told by Homer in The Odyssey. The Golden Fleece is the object of another famous quest from the tale of Jason and the Argonauts in Greek mythology. Perhaps the most famous quest motif from fiction centers around the Holy Grail; this is an interesting use of the motif, in that those who tell tales of the Holy Grail not only get to deal with heroes who succeed, like Parsifal or Sir Galahad, but also with heroes who fail, like Sir Lancelot.
A familiar modern literary quest is seen in the tale of Frodo Baggins's quest to destroy the One Ring in The Lord of the Rings. The One Ring, its baleful power, and the difficult method which is the only way to destroy it, is used by Tolkien to tell a meaningful tale of friendship and the inner struggle with temptation, against a background of epic and supernatural warfare.
In the hands of lesser artists, unfortunately, the arbitrariness of the quest, the MacGuffin character of its objects, and the thin plot devices used to make its accomplishment difficult, make the quest motif one of the more obvious and least satisfying devices in fiction. This has unfortunately not prevented the quest device from being used in a thousand mediocre computer role-playing games.