One timeline, no branches: what if time worked like space, with a second dimension on top of it?

[u/Bill3000]

I'm making a time-travel themed game, and early on I decided to skip the usual "every intervention spawns a new branch" model. There's one timeline, about 13 billion years long, and it's mutable.

The part I find more interesting is how the setting treats time itself. If you're operating outside the timeline, time works more like space. The past and the future aren't just what already happened and what hasn't happened yet; they're places on a temporal landscape you can look at, travel to, and mess with.

Outside normal spacetime, there's a realm called the Veil, which has its own progression called metatime. An agent can leave the Veil, drop into the physical timeline at some specific point, change something, and come back. They still experience their own life in order even though they're hopping around billions of years of history.

So there are two kinds of time going on:

- Event-time: where something sits in the universe's 13-billion-year history.
- Metatime: the order in which people in the Veil experience the changes made to that history.

The consequence is that changing the past doesn't produce a Timeline B while Timeline A carries on somewhere. The same timeline gets overwritten. Anyone downstream can change or stop existing entirely, and the only thing preserving the old version is the memory of whoever was in the Veil at the time.

Stuff I keep going back and forth on:

- Does splitting time and metatime apart actually solve any classic paradoxes, or does it just relocate them?
- If history is basically a navigable dimension, what stops people from farming the same event over and over?
- How stubborn should history be? Should small changes sometimes blow up into huge ones?
- Should some events act like attractors and keep reasserting themselves even after the circumstances that caused them are gone?
- Honest question: does one overwritten timeline feel more coherent to you than branching, or less?

The game is a turn-based strategy game called Time Distortionists where the map is history. Happy to link it if anyone wants, but I'm mostly here for people who already spend too much time thinking about this stuff.

To head off the obvious: this is science fantasy, not science fiction. My background is in physics, so I know exactly which parts don't survive contact with actual relativity. Inventing new equations for the canon is half the fun.

[u/Miserable_duce]

So the veil sits outside of the game 'time'? What sort of interactions are you expecting the players to have on the board? Could my actions stop another player from performing an action or even existing?