If you saw the TV show "Sliders" in the 90's or read/watched/played pretty much anything (Chronicles of Narnia/GURPS Infinite Worlds/His Dark Materials/Bioshock Infinite/superhero comics/etc.) with a multiverse consisting of multiple dimensions/universes/timelines, that's the most basic way to describe this RP.
HOWEVER, I should warn you it's not that simple. While most of the sci-fi will be soft and magic will even exist, this RP will attempt to make realistic use of the "quantum multiverse" (read: every time something, anything, happens it causes the timeline to split into versions of itself where all possible outcomes have occured) and the butterfly effect will be extremely powerful.
How powerful? Here's some brief descriptions of timelines that I've come up with. After their divergence point, they have nothing in common with history as we know it.
(NOTE: None of these timelines are meant to discriminate against or for any race, nation or religious viewpoint. Furthermore, no accusations are being made, and any claims of affiliation of a historical figure with any other historical figure or historical social movement made without evidence to back said claims are not meant to be taken seriously, but rather as just another way of making the plot interesting. In other words: I try to make unfriendly organizations be from whatever race makes the most sense for the location and/or fictional timeline. I only give famous people fictional/unproven dark secrets if it affects the story in an interesting way, and in three different timelines a person might have a dark secret behind action(s), a different dark secret behind the same action(s), and no dark secret behind the action(s), respectively.)
1 - Real Life. Impossible to visit without creating a "singular divergence".
64 - Diverging as Timeline 64 in the 1970s, several corporations that don't exist in Timeline 1 came into existence. Goliath Entertainment, Draconic Studios (run by Xander Chaser, Alex Chaser's father), Phox Games, Video Gadgeteer... And in the wake of this shift in the history of video games was a shift in history as a whole. You wouldn't think that the Phoxole, Draco System or GamePlayer would have a major effect, but they did. By 2014, HTML+ v3 was the standard for a world wide web entirely incompatible with our own, virtual reality was already on the market for 2 years, not a single presidential candidate since Reagan was anyone recognizable to timeline 1, and augmented reality was well on its way to becoming an equal to the internet.
86 - Rome is not known in our universe for having a very good ending, but nobody truly knows the reason for its fall. Over 200 different theories have been devised, with little support for any of them. But what if Rome had never fallen? What if Romulus Augustulus had never been deposed in 476? What if the Germanic tribes had all been pushed aside or assimilated through their might? It may sound unlikely, but after Timeline 86 diverged, that is exactly what happened. Over the course of its 3,000-year reign, Rome remained strong, eventually growing to encompass most of the civilized world, with the exception of numerous smaller nations surrounding its borders and the majority of islands, particularly Japan, which only vaguely resembles the Japan we know, and Australia, still mainly inhabited by its Aboriginal peoples. Society progressed, technology advanced, language developed. In this world, traditional Roman ways are beginning to decline, in favor of a secular, egalitarian, constitutional monarchy headed by Januarius Griseus. But not everyone is happy living under Roman rule anymore, and Griseus' position of leadership is now in jeopardy as a result...
413 - Space is a big place, and not a particularly friendly one either. What happens when it attacks Earth? In this timeline, the world was well on its way to becoming a YeAST (Yet Another Steampunk Timeline) when a beam from a pulsar irradiated the entire planet some time in the early 20th century, killing all life. It also caused the water to boil off into space, leaving Earth with no oceans and thus no tide. And of course water is HEAVY, so gravity is significantly affected. And that's bad news to Timeskippers, because inter-timeline travel relies on the Earth's gravitational field to keep travelers from arriving on the other side in deep space...
666 - The Dark Ages are extended after the church institutes the burning alive of the entire families of any peasant who lets themselves live beyond a certain quality of life "designated by god". The European feudal system was also extended by threatening lenient lords and barons and dukes with the same fate. A campaign similar to the crusades occurred in the 1600s which annexed the Arab nation. Though a renaissance started in the 1800s, it was cut short by the ever-corrupt theology that barely resembled the teachings of Jesus anymore. By 2014, North America had only vaguely been charted by missionaries, and the system in Europe was cemented so thoroughly that it would take an event that would rock the hierarchy itself of the church to bring it down.
802 - Japan does not attack Pearl Harbor, which results in the US never using the atomic bomb. After the Japanese have solidified control of most of the eastern hemisphere by the 1960s, they hit Europe, Australia, Russia, and North America with surprise atomic bombings, causing the deaths of millions and paving the way for a Japanese empire whose control only fades in southern Africa and South America. Though paling in comparison to the Japan of timeline 1, they develop telecommunications up to 1970s levels by 2014 which holds their control over the world in ways the British only wish they could have done.
911 - A NAAT (Not An Average Timeline), this timeline diverged from timeline 1 on September 11, 2001, when a flock of birds destroys the engines of one of the to-be-hijacked planes on takeoff. The plane aborts successfully, but the angry terrorists take the plane hostage, demanding that they be given a plane to leave the country (which they actually were planning on using to carry out the plot). The second plane to leave the ground blows a tire while taxiing and is forced to abort, angering those terrorists too. Once two planes are simultaneously held hostage under suspiciously similar ransom conditions (a plane, no cash), the CIA quickly figures out what is going on and grounds every plane in the country before 9/11 can occur. This changes the history of the entire following decade, including exposing the Bush family's connections to Al Queda and shattering several international alliances.
1984 - This timeline diverged in the early 20th century. A YACHT (Yet Another Cyberpunk Hell Timeline) to the core, Timeline 1984 is ruled over by the enigmatic Machine, supposedly an AI that is perfect in its ruling over mankind. But then why are there massive slums and shining arcologies?
1993 - Australia is discovered 250 years later than in our timeline. By 2014, England and France's homelands have destroyed each other with chemical weapons, America is three countries (Cascadia, The Confederation and the Union), Quebec City is the new French capital, the Russians have absorbed Mongolia and declared war on China TWICE, and Spain is laughing all the way to the bank with an empire spanning from Mexico to the tip of South America to their name.
2582 - The automobile is not a certainty across the multiverse. In this world, Pennsylvania Railroad and B&O Railroad got wind of the Great American streetcar scandal in the 1930s from a whistleblower who was ignored by the government and the press. Realizing if it were to succeed the days of the railroad would be numbered, they sabotaged the conspiracy. As a result, mass transit flourished in North America and cars fell out of use woldwide. Though air travel displaced the railroads in the 20th century, there is no US Interstate Highway system. 2014 is the 50th Anniversary of the Los Angeles Monorail system and the opening of its station on the Global Maglev Network. Reportedly a terrorist group (actually acting on behalf of Big Air) is out to destroy the station however, but the authorities assure the public they have it under control. What could possibly go wrong?
5190 - For centuries the caucasian race has weilded most of the power throughout the world. What would a timeline where that was not true look like? What if the world was more equally distributed? Or barring that, what kind of world would exist without the white man? In this timeline, the Huns managed to annihilate the Roman Empire plus all the Roman-conquered peoples. Shortly afterwards the Huns underwent a civil war that destroyed them. Europe was left uninhabited for centuries, and China is unable to find suitable markets for silk and opium which forces them to do business with the middle east, which redirects the silk road to Egypt and eventually the rest of Africa. Events conspire to eliminate India and the Arabs from the equation, and the Afro-Egyptian and Chinese empires (the latter of which also annexed Japan) discover the horrors of the atomic bomb just before it was too late, paving the way for an "Afro-Asian Alliance" to prevent nuclear holocaust. Unfortunately, by 2014 the Afro-Asian Alliance is poised for nuclear war with the Aztecs.
6735 - What if Magic was real? Before this timeline diverged from 5190, the Huns managed to annihilate the Roman Empire plus all the Roman-conquered peoples. Shortly afterwards the Huns underwent a civil war that destroyed them. Europe was left uninhabited for centuries, and China is unable to find suitable markets for silk and opium which forces them to do business with the middle east, which redirects the silk road to Egypt and eventually the rest of Africa. However, a secret civilization grew from the 9th century onward through the magical understanding of the aboriginees of what we know of as Australia. From that point on, this timeline splintered off from Timeline 5190, and in the 16th century the powerful magics of the "Jadu Bhumi" as the Indian Navy dubbed them and their continent became known to Afro-Eurasia. After the Chinese and Indians get a hold of the magic by exchanging technological secrets for them, they formed the "Asian Federation". The Arabs joined shortly afterwards and the new force conquered Egypt. Meanwhile, the "Jadu Bhumi" sent colonial forces in newly-developed magitech ships to the east, discovering the Aztecs. The three groups race to conquer as much of the globe as they can. By 2014 there are three separate telegraph networks proprietary to the three mega-nations.
6777 - The Shinkansen trains, whose concept dates over 20 years before the trains began running, transformed the entire country of Japan, and cemented high-speed rail as a major component of transportation networks the world over. But if they never caught on? In this timeline, the Shinkansen idea was not revived after it was forgotten during WWII, causing Japan to become a country where the automobile is king. With space limited, the country soon became a massive city-island where underground highways criss-crossed beneath the buildings, and cars, trucks and busses are powered by an overhead grid like bumper cars to keep pollution from choking the tunnels and reduce the risk of fires. By 2015 the nation is a true cyberpunk nation where the cars drive themselves, as the only way to be passingly efficient with highways in Japan is to remove the driver from the equation.
8742 - After Tesla accidentally blows up Boston in the late 1800s using an experimental nuclear fusion reactor, fear of technology reaches a fever pitch that persists to 2014, and the Western World stagnates due to the slow onset of a new dark age. Which is bad news for a Timeskipper needing supplies.
Aside from timelines constantly branching out on their own, the so-called Timeskippers are a unique case. By leaving their home universe, they have removed themselves from that timeline, and unless they have that timeline "bookmarked" somehow they can never get back to it. The other effect is that they cause a "singular divergence" because their arrival in a timeline creates an entirely new timeline just for the fact that they popped into existence out of nowhere.
It should be noted that when a character leaves a timeline, they cause the timeline to be "locked" to their destination for about one month, allowing the characters to travel more-or-less in a group.
Anyway, this RP will require 2-3 paragraphs per post, unless you can come up with some really good material that is shorter. No double-posting. If you have to leave the RP for any reason or length of time, or want to jump in mid-RP, please PM me and we can work out a way to fit it into the story. Doesn't matter if it's permanent, indefinite or temporary.