Story Arcs are special setups in the game that reveal a piece of the story content over a series of missions from a contact. The number of missions can be small or large, but all story arcs function as their own story within the story of the game, or expand on the story of the game.
Upon completion, a souvenir is awarded by most arcs, which allows you to read the storyline at a later time. This summary is saved in a user's clues menu. Additionally, completing a Story Arc will net the player a significant experience bonus, and for most arcs, a certain number of Reward Merits.
- Main arcs (also called "major arcs") are signified by a book icon in the arc contact's window, with a blue outline and bookmark. These arcs tend to have to do more with the story of the game, or the story of a certain faction within the game. There are some exceptions.
- Shorter, minor arcs (also called "mini arcs") are signified book icon having a green outline and green bookmark. These arcs tend to deal more with the contact's own story, rather than expanding on the story of the game. Like main arcs, there are some exceptions.
- Note that for heroes, the zone-specific arcs from contacts in The Hollows, Faultline, Striga Isle, and Croatoa are all minor arcs; for both heroes and villains, the missions in Rikti War Zone are also minor arcs.
Most of the content for heroes comes in the form of main arcs, with only a few scattered minor arcs. Most of the content for villains comes in the form of a large number of minor arcs.
Prior to Issue 17, characters could have a maximum of two active main arcs (blue book). With the increased active mission list from three to seven in Issue 17, the maximum number of main arcs that can be active was raised to five. Contacts will not give missions that start a main arc if you are at the limit. They do not prevent minor arcs (green book) from beginning, however.
While there may actually be an upper limit to minor arcs, there is no functional limit as there are reports of characters with as many as 46 minor arcs open at once. Active minor arcs should not prevent main arcs from beginning. There are, however, some contacts whose arcs count toward the "two main arcs" limitation. If there is a mini arc active for any of these contacts, it must be completed as if it is a main arc.