A mission string (a.k.a. thread or storyline) is a series of missions offered to a pilot by one of the governments, corporations, or other entities in the game. Typically, mission strings will begin with simple tasks such as pickup and delivery, then progress to more difficult and dangerous undertakings such as capture or destruction of ships. Mission strings are generally divided into major or minor categories, depending on the number and nature of tasks required. A player may undertake a number of minor strings, often simultaneously, but acceptance of a major string prevents that pilot from undertaking any other major string.