Thursday, September 27, 2007

Adventure Game w/Fine Tuned Time Travel

While I think about the painting game described earlier, I can't help but think about a time travel game.

I've always wanted a time travel game where your control over time was far more flexible than it usually is. I don't mean the momentary time travel you find in Braid or Prince of Persia: I mean real time travel.

So here's the idea: the game is basically an adventure game. Much like any other adventure game, it features a large amount of running around getting items and solving puzzles.

UNlike any other adventure game out there, this one has a line running across the top of the screen, marked with logarithmic time (first inch is one minute, second inch is an hour, third inch is a day, etc). You are a dot in the center of the line, and the line slowly slides left past you. Actually, you're located just below the line, with a little line of your own behind you.

Here's an example of how the first scene might play out:

You arrive at the water park, but the gates are closed. The man behind the counter tells you that they open in about five minutes, if you want to wait. On the timeline, a glimmering gem is added. A helpful arrow signals that you should drag yourself to the glimmering gem. (The gem, if you mouseover it, says "water park opens".)

Dragging yourself up and over will move you to whatever time you drag to. However, this is not a "skip" - if you drag yourself five minutes forward in time, everyone else perceives you as having stood around for five minutes and you automatically fill in any events that happen locally that you could see.

So you move forward, go into the water park and, I don't know, steal a data disk. Then you decide to rewind time. Drag yourself up and to the left. Except that actually rewinds time: you're standing back outside the gate. The disk is in the water park, not your hands. You never took it. The line representing your personal timeline does not stretch forward and then back: as it always has, it starts from scene one and meets you wherever you are.

But there is an event on the timeline: "Hero steals data disk". If you were to simply drag forward, time would progress as it did before, and you would automatically steal the data disk. Because that's what you did. If you replayed the section, you would negate the event because you're doing something else.

Simple enough.

However, that's dragging UP and to the side. There's also dragging UNDERNEATH and to the side (unlocked a bit later). This is an actual time skip, where you physically vanish and travel in time. This means there can be two of you, or maybe none of you. It makes your personal timeline either go loopy or get all dashed.

Your old selves cannot see your present self or feel your work, of course: the way the timeline works prevents that. Similarly, no matter how many of you are present, NPCs will only detect one of you. Unless interrupted, they will continue to perform the events set in their timeline.

So if you dragged DOWN and left after grabbing the disk, you would rewind to before the place opened. You wouldn't be standing outside the gate: you'd be standing wherever in the park you were standing, but it would be before the park opens.

You could then walk to the entrance, let it open, and then walk out and hand yourself the disk. The system looks forward in your original timeline, sees that you are slated to steal the disk, realizes that ain't gonna happen now, and collapses the time loop. You are now standing outside the freshly opened gate with a disk in your hand, having never time traveled.

Of course, you don't have to give yourself the disk. You could simply proceed forward without any issues. So long as you don't interfere with yourself getting the disk: this causes a paradox. Paradoxes are bad, and have to be resolved either manually (un-interfering) or by collapsing the loop as described above. Collapsing a paradoxed loop is rather unhealthy, though.

Most of the puzzles probably depend on there being more than one of you. Because that's fun and not hard to program.

This system can easily get very complex. For example, you might do a lot of looping in that area, and after a few hours of real play you'll find that your timeline looks more like sheet music than a line. Every event you are "slated" to do because you already did it appears on the line that did it, but it can still get unbearably complex. Collapsing loops can become a necessity, but it can also have unintended consequences, since all events you would have done in the loop aren't slated to get done anymore. They now never will automatically have happened, if you see what I mean.

(This is particularly bad if you travel a lot in your time loops: non-local events aren't displayed, and timelines that approach those events wander off the screen... Messy!)

You aren't the only time traveler, of course. Some items are "temporal", in which case they either stick to their time line (so you can't time skip with them) or stick to your time line (so you can rewind and keep them).

Some people are temporal as well, which means that if you time skip, they remember what you already will automatically do in your "old" time line.

A few people are even time travelers, although nowhere near as sophisticated as you. There will be a particularly interesting pair - one travels normal through time, the other travels backwards through time. They frequently give each other something to give back earlier in their personal time line (later in the recipient's time line).

All of these "chronally advantaged" people will have visible timelines of their own, of course...

Obviously, this "adventure game" features a bit more open-ended scripting than most. Think of it more as Quest for Glory or late-game ChronoTrigger.

That's just the time aspect... you could also make it so that you could "rotate" the axis so that instead of being time, it's parallel dimensions! Remember, traveling to alternate dimensions means you change to your alternate-dimension self...


Alternate version: as above, but it's a tactical game a'la Disgaea or Final Fantasy Tactics. Time hopping (going "below") can't bring your people back to life, but time scrolling (going "above") CAN... but at times you'll be forced to fight other time travelers at points in your career of their choosing...


refaal said...

I looked all over your blog for your email address but i couldnt find it. So, im sorry for this nonsense reply, but id like to tell you that i read your 'drawing styles' post ( ) and i agree 92% with it. Swim against the stream is a fine (and dangerous) art, and you did it well there. For that, Im your fan!


Craig Perko said...

I should probably post my email addy. :)

Funny, I get more hits and comments on those old art posts than I get on my recent work...

Jim said...

All Things Devours worked a lot like that. You have six minutes to sabotage a lab developing a prototype time machine. Doing this and getting away with it requires extensive use of the time machine, since you need to be in multiple places at once.

Inconsistencies are handled very simply: if you or anyone observes direct evidence of time manipulation, the object being observed is totally converted to pure energy, destroying a good portion of the city. Which is why you're sabotaging the project, see.

It's a very satisfying, tightly constructed puzzle box. Had to break out the paper and pencil to chart the timeline of where each of me needed to be when.

Craig Perko said...

I'll look into it, thanks!

Glenn said...

Sounds a lot like the Continuum role playing game. While you can't rewind and fast forward within your own timeline, you can hop through time at will (the 'average' time traveler can make up to 10 years and/or 10 miles worth of time jumps in a given day before needing to rest).

Temporal paradoxes are nasty - every time you create a paradox (or someone else creates a paradox that affects you) your time-traveling ability would degrade, and you would experience nasty physical symptoms (the equivalent of damage in most game systems) until you somehow solved the paradox. You did this by either causing paradox to the person who hit you (they get your paradox level+1 in paradox) or else by fixing the event in the timeline that is currently causing the problem.

An example from the book is: You take a shower in the morning. Another time traveler is annoyed at you and goes back in time before you showered to steal your shampoo. This causes you paradox, because in your timeline you used that shampoo, which now will not be there. So either you have to go back in time to replace that shampoo (by figuring out from your own memories or a bit of research exactly where the timelines are screwed up) or else by hunting down the other time traveler and stealing the shoes he was wearing when he would have stolen your shampoo (since he would then incur the paradox from not having an item when he stole your shampoo, and everything else in his timeline after the point where he would have put those shoes on is rendered 'suspect'). The problem with the second option is that if he goes back and replaces his own shoes in his timeline, suddenly you're back to the point where he went and stole your shampoo before you used it, putting the paradox back on your timeline.

This is called 'time combat' and generally ends with one party or the other with so much paradox that they cease to exist within the timeline as sentient beings (you cannot be destroyed completely this way, you become something like a ghost, repeating the actions that are causing you paradox endlessly until another time-traveler fixes you or takes you to the far future where you can be 'treated' for paradox).

Craig Perko said...

Yeah, I wanted to do it in a way that could be done in a computer simulation. Continuum is not only a bit flaky rules-wise, but requires huge amounts of GM intervention.