When two or more outcomes occur as consequence of an event, each outcome can be considered an alternate reality, possibly explained by the fact that some events occur in different timelines or universes. The contradictory events can be considered as alternate timelines (if they are a result of time travel), or as alternate universes (when probability and quantum mechanics make things unfold differently without any travel through time occurring).
- In general terms, though there are many alternate realities in fan fiction, the term Kelvin Timeline is used for the alternate reality created by Nero's time travel in Star Trek.
In the 2360s of the prime universe, Beck, Seifer and Cell travelled to this reality aboard an alternate timeline-Delta Flyer equipped with Berlinghoff Rasmussen's temporal displacement drive, modified with a Mirror universe multidimensional transporter device. In this alternate reality of the 2260s, they briefly encountered and were captured by the USS Enterprise. (Star Trek: Phoenix-X: "Displacement Syndrome")
- In "Displacement Syndrome", this alternate reality served as a soft parallel to the timeline in Star Trek: Phase II by references to events in that series.
In 2410, Harley Menrow, Yuffie Samya, Andrea Reynolds, Iviok and McCary were brought to Nibiru aboard the Breen ship Darkseid through a black hole by Mayhem to help destroy the planet before it reconfigured space in the prime universe. The Captains then tasked themselves to stop Oroku Seifer from becoming the local population's new god. While there, the Captains discovered Mayhem's intentions and stopped him just as the Nibiru were tricked into ending their dangerous modifications of space and time. Everyone returned to the prime universe using the Darkseid and the black hole they arrived in. (Star Trek: Phoenix-X: "Nibiru")
|existence of the expanded universe|
|dimension - history - multiverse - space - space-time continuum - time - universe|
|alternate dimension - alternate timeline - parallel universe - pocket universe - subspace and hyperspace|
- In fan fiction and canon stories alike, an alternate reality can be used as a main story point, or it can simply be created after the fact to explain why events contradict each other.
- For example, the fan series Star Trek: Pendragon is based on a main story point that they are an alternate reality where things happened very differently than they did in the history of Star Trek canon.
- Other series that end up contradicting each other as a result of not being related to each other are usually explained as being alternate realities that differ in superficial ways not related to the story. Example: One ship has different registry numbers in two different fictions.