Premise

Phase RPG is a Multifandom World building sandbox RPG based on Ringworld by Larry Niven.

Welcome to the Ring,
where an ancient program created to “phase” in people and pieces of worlds from across time and space is still running long after its creators perished. Once, the worlds were spread evenly across the ring's massive surface. But an emergency protocol has caused a re-phasing, causing most all the worlds to be pulled to sector one. They overlap and criss-cross, and the Complex itself takes up a large portion of what appears to be Manhattan's Upper West Side. What has happened to the rest of the ring remains a mystery for the moment.

Two sorts of people are brought here: the fully phased (PCs), brought by the computer to help run and maintain the ring, and the partially phased (NPCs), shadows of those who come with the phased territories. They come and go, disappear and reappear, and even old friends are not always friendly, trapped as they are between the Ring and their own time and space. There’s no way to get home, but with a surface area of three million Earths to explore, do you really need to?

Arrival
This is typically the first experience in the game for every character.

You were just going about your business when there was a flash of light and a feeling of being pulled into darkness…and then nothing.

You wake up in what appears to be some sort of pod, which is already opening up for you to exit. You’re in your clothes, anything you were holding or had strapped to your body is still there. The room you are in is small and a bit metallic. There’s another empty pod across from you. It’s quiet, save for the hum of machinery and the mutter of distant voices.

“Phase complete,” says a slightly odd, somewhat female computerized voice from out of nowhere. “Report for debriefing.”

The door to the room opens into a huge hallway, and you realize you are in some sort of massive underground complex. There are some running lights trying to lead you down into the center of the complex to some sort of conference room, and there hovering above the table is a hologram, and once you realize what you are looking at, things make just a little more sense--but only a little.

You aren’t on a planet. You’re on the inner surface of a massive ring around a distant star. The computer calls it a “Niven Ring” And as you look, the computer lights up a region of ring not that far from where it says you are, and starts chattering about a “phase initiated.” Pictures appear on a nearby screen, and you realize that this new region looks very familiar.

It looks like home.

Curiosity drives you upwards then, into the section of the Complex which rises high above the ring surface. From the roof of the building, you see a strange mix of cityscapes and wide open spaces, mashed together as if different worlds had fallen on top of each other, spreading out for as far as the eye can see, which is surprisingly far--for on the ring, there is no horizon.

Almost directly above is a star. Not Earth’s sun, because that sun was never so ruddy in the midday. It makes the sky just a little more indigo than you’re used to. There is something strange about it, and if you stand there long enough, you might realize just what it is: the star does not move. And if you stand there for hours, you will finally see a great, almost frightening shadow rolling across the sky, blocking out the star, bathing all you can see in an impenetrable darkness and revealing a awesome but terrifying sight: a massive, near-infinite arch cutting the sky in half directly overhead. There are a few stars, but none of them are familiar. You start to get the feeling that what you are seeing might not be stars at all.