Eightspeed

Eightspeed is a fictional velocity metric used in science fiction and some tabletop role-playing games to describe propulsion or data transfer at eight times the speed of light. In most settings the term is associated with a speed of 8c, though the exact implications—such as time effects, acceleration limits, or how it interacts with relativistic physics—vary by author or system.

Within stories and games, eightspeed enables interstellar travel across large distances in comparatively short times. Some narratives treat it as a straightforward multiple of c, while others portray it as a distinct regime governed by special propulsion technologies (for example, warp drives, hyperdrives, or tachyonic systems). In other cases it functions as a narrative shorthand for "extremely fast" without specifying the underlying mechanism.

Because eightspeed exceeds the universal speed limit for information and matter in known physics, it is not considered physically realizable outside of fiction. Writers use it as a plot device to explore causality, communication delays, or pacing in spacefaring contexts, and game designers may implement it through specific rules, limitations, or costs.

Notation and variants: Eightspeed is commonly written as 8c or as a warp factor that implies eight times light speed, depending on the setting. Some systems treat it as a dimensionless stat rather than a direct velocity.

See also: Light speed, Faster-than-light travel, Warp drive, Hyperspace, Tachyon.