|“||Once upon a time, there was a world just like ours. But with one small change that changed everything.||„|
| — God|
in "Once Upon a Time"
The alternate universe is a realm of existence inhabited by mortals, angels, demons, and gods. Earth, Heaven, and Hell are contained within it, created by God. It was an exact copy of the Universe up until July 27, 2000.
|“||Yes I put Chloe in Lucifer's path. But what if I hadn't? Most people can't get that answer. But I can. Just one of the benefits of being God||„|
|– God, describing his experiment|
The universe is a physical realm created by God to show what would have happened if his son Lucifer had not met Chloe Decker. To do this he manipulated events so that John Decker was never murdered, thus removing the reason for Chloe to join the police and instead remain an actress. This had a butterfly effect of completely altering the lives of hundreds of people.
Due to remaining an actress and becoming famous as Bonnie Gennaro in the Weaponizer film series while her father went on to become a lieutenant, the lives of Dan Espinoza, Ella Lopez, Linda Martin, and Charlotte Richards were particularly affected. Due to never marrying Chloe and having Trixie with her, Dan eventually gave in to his more corrupt tendencies and by 2018 skims money out of the evidence locker, and has a very antagonistic relationship with Lucifer. Ella was inspired by Chloe's character to become a mechanic and steal cars, which eventually led her to know Lucifer. Linda became the host of a show called Dr Linda with help from Chloe. Charlotte Richards is still alive and is Lucifer's attorney, though is very corrupt due to never trying to change. Similarly because Lucifer never met Chloe, this meant he remained an arrogant club owner while Amenadiel and Maze have been affected as well. Amenadiel has been forced to remain on Earth due to his inability to send Lucifer to Hell, as without Chloe he never learned about Lucifer's mortality. Maze is still loyal to Lucifer, and seemed to have formed a cult with her as a leader.
- It is unknown if this universe continues to exist alongside the original universe. If it does, that would make it part of the Arrowverse though it lacks a designation. Unlike the original universe, which is designated as Earth-666, the alternate universe would only be part of the new multiverse as the original was destroyed at some point between 2011 and 2016 and was later recreated after Crisis on Infinite Earths, and God presumably didn't create the alternate universe until 2018.
- It can be presumed that Uriel is still alive since Lucifer and Amenadiel mention him.
- Many characters, like Goddess, Malcolm Graham, Marcus Pierce, and Sinnerman, are not mentioned, so it is unknown what happened to them.