Planck Time: A confusing game about time travel

Setting

The far future: time travel technology is now commonplace, as well as all sorts of future tech that lets humans move and think at supersonic speeds. Various factions use them all to fight a very confusing war across time and space. Eventually they figure out that the only way to win is to travel as far back in time as possible (which means the invention of time travel, since time machines work like time portals, not like time ships) and secure that first second.

July 1st, 20XX: Dr Brown has build the very first time machine. As a precautionary measure, a powerful explosive is strapped to the device and rigged to blow if any unexpected object comes out of it. Brown turns on the machine. In the single second between the opening of the time portal and the room’s utter annihilation, far future warriors jump out and fight each other, using future tech and time-travel tricks. There can be only one survivor.

Gameplay overview

Okay, this is about time travel so it’s going to get confusing. Here’s a (very very early work-in-progress) mockup of the board, maybe it’ll help:

Each line represents Dr Brown’s lab at a specific instant after turning on the time machine. Players each control one character, represented by a meeple of their colour that starts out of the top-most, left-most square. Each player can do a few actions during their turn (moving around, fighting other players, maybe interacting with stuff in the lab). One turn represents about 0.2 seconds.

At the end of the turn, their meeple is laid down (it’s “inactive”; it’s just history, and can’t make a different decision than the one it already made) and a new meeple of their colour is placed one square down. If that leaves them on a red square, it means the explosion outpaced them and they die (or just get wounded? mechanics aren’t fixed yet). The goal is to end up as the only meeple in the right-most, lower-most square. That means your warrior jumps off the window and escapes, while everyone else is trapped in the explosion (or already dead). When that happens, the trail of inactive meeples shows the history of the fight: where each player was at the end of each instant.

Sounds simple enough? That’s because I haven’t talked about TIME TRAVEL! See, each player carries an advanced portable time machine. They can use it [some amount of times] to go to the past (that is, up), or possibly even to the future. Let’s say that the green meeple in t=0.8 turns on their machine right before burning to death and uses it to go back to t=0.4. Now they can come to the aid of their past self and kill blue right there. This will propagate forward in time and erase the t=0.8 blue meeple from existence. Except maybe blue will choose to flee to t=0.6 before the information propagates to them, beat up the green meeple that’s still there, and then team up with their t=0.6 self and go all the way back to t=0 with superior numbers. An event can’t erase you while you’re in that event’s past, you see. But then at t=0, maybe the green meeple will fight off this sudden blue invasion, leaving black time to run away from the explosion, and black still has a fully fuelled time machine. It’s anyone’s guess who will be the last meeple standing at t=0.8 in this timeline.

How could this possibly work, mechanically speaking?

It doesn’t.

But how can it be made to sort-of-work-if-you-squint?

Gameplay details

As a general rule, whenever an active (upright) meeple ends up in the same square as some inactive meeples, the inactive meeples all become active. (This represents people making different choices in response to e.g. the sudden appearance of a time traveller.)

• You work on a single row at a time. Every player gets to use all of their active meeples in that row (to move, fight, time travel etc.) Even if a meeple uses time travel to move to a different row, you keep playing in the current row.
• When everyone’s done with the current row, any active meeple in that row is made inactive, and an active meeple is added one square below.
• Then you look for the top-most row that has at least one active meeple in it. That’s the row you start playing in.

I hope this will lead to ok gameplay. However, it leaves in a few paradoxes that are hard to keep track of without a computer. Notably, meeples don’t really have a history; the fact that a meeple has been killed at t=0.6 will never propagate to its future self at t=0.8. I don’t like it but I haven’t found a clean solution yet.

Also, when a meeple at t=0.6 that started out in row 3 moves to row 4, some information is lost (the fact that it was in row 3 as the t=6 instant started out). This also means that a meeple one one row who gets re-activated multiple times over the course of the game ends up doing tons of different things in those brief 0.2 seconds.

Initially, this game was called Planck Time because each instant was literally a Planck Time, so each meeple only got to do a single action whose effect would only affect the next row. But this requires a lot of row for any serious activity to happen, which causes a lot of busywork with the make-inactive-then-add-active-meeple-on-next-row action. (It’s also physically dubious; no amount of future tech will let you do anything noticeable in a Planck time, least of all destroying a room with explosives.)

On the other end of the scale, I’ve toyed with versions of this idea which worked on a scale of days instead of milliseconds, and on a physical scale of an entire city instead of a single room. But then you lose out on various cool things that short scales allow, like that slow-growth explosion (which you can also add as a player-controlled ability; throwing a grenade is bad news for future meeples).

Status

I wrote a little content for the “days scale” version, which also included time distortions (e.g. suddenly a whole row disappears; because, uh, time magic). It’s quite far from playable though, and also not very good.

Idea shelved for now.