A quest chain (aka chain quest, questline / quest line or quest storyline) is simply a series of quests which must be completed in a particular order. A quest which have to be completed in order to access another quest is referred to as a "prerequisite", while a quest which becomes available after completing other quests is referred to as a "followup" / "follow-up". Quest chains are fairly common in World of Warcraft, albeit most of them being short. Most only consist of two to three quests, but some may include more than ten. A few quest chains are somewhat famous, such as the Scepter of the Shifting Sands chain.
Quest chains will normally give better rewards than normal quests. Sometimes they will also grant achievements, such as .