A Misjump is an attempt at jump space travel that has gone catastrophically wrong resulting in potential destruction at the worst, and travel to unintended destinations far off the intended course at best.
Please refer to the following AAB library data for further information:
- Jump Drive
Misjump: A misjump is an unpredictable random jump. Each time the ship engages in a jump, a misjump may occur. The odds go up if using unrefined fuel (and not equipped to do so), if within 100 planetary diameters of a world, or if a ship is within ten planetary diameters of a world. Some ships may be destroyed altogether by a misjump.  Other ships misjump enormous distances or even enormous amounts of time, from a number of weeks spent in jump space to even rumors of years or centuries stuck in jumpspace. 
History & Background (Dossier)
Sometimes a jump goes wrong. Catastrophic failures (called misjumps) can destroy the ship and its crew. Other failures can destroy a drive or send a ship in the wrong direction. Some misjumps reduce a Jump-6 to a mere Jump-1, or convert a Jump-1 into Jump-10, 20, or higher. The fact that misjumps can cause the distance traveled to exceed the normal range is an indication that further research is necessary in the field of jump technologies.
References & Contributors / Sources
- Marc Miller. Starships (Game Designers Workshop, 1977), 5.
- Project Farstars, an article in Challenge
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science
- Don Perrin. Starships (Imperium Games, 1996), 6.Marc Miller. Starships (Game Designers Workshop, 1977), 6.Thomas L. Bont, Robert Prior, Christopher Thrash. Starships (Steve Jackson Games, 2003), 6.
- Don Perrin. Starships (Imperium Games, 1996), 5.Marc Miller. Starships (Game Designers Workshop, 1977), 5.Thomas L. Bont, Robert Prior, Christopher Thrash. Starships (Steve Jackson Games, 2003), 5.