When you go back in time, where do you end up? There are several options:
- You remain at exactly the same geographic location: Basically, you don't go anywhere. More accurately, you arrive on Earth at precisely the same longitude and latitude you left from. This ignores the fact that the planet actually moves. Even if you assume you automatically stay on Earth, you'll still run into the issue of continental drift if you go back far enough.
- You end up in outer space: Why? Well, the Earth is moving around the Sun and it pulled away from you when you traveled through time. Pretty much only possible if your method of time travel completely removes you from the Earth's frame of reference.
- You end up somewhere else for no explained reason: The real reason is almost always to serve the plot, of course. If you were in California and you went back to the year 1347 you wouldn't want to end up in the pre-Columbian wilderness, would you? Sure, there would be Native Americans around, but if you went to 1347 you would be hoping to experience The Middle Ages, right? This can also occur on a smaller scale, i.e. you end up on the other side of town for no reason.
- You get to program your destination: Basically, a justified version of the above (and possibly a way of dealing with the above the above). Very common. Essentially, this means that your Time Machine is not only capable of time travel, but also teleportation — it just engages both at the same time. Think about it — if you input a destination, but keep the time the same, you can instantly travel anywhere! In a sense, this may be the most scientifically accurate scenario, since according to Einstein's special theory of relativity, teleportation and time travel are actually equivalent. It is not possible to travel instantaneously from one location to another without appearing to some observers to have traveled backward in time.
- You end up nowhere at all: You end up in different dimension, or otherwise not in the known universe. Usually this means there was some sort of problem. Broken Time Machine?
Game and Story Use
- Figuring out how time travel works in the setting is very important for the GM to do. It sets the tone of the campaign, and determines both what kind of tricks the PCs can pull, and what kind of challenges they'll face.
- If the method of time travel also grants teleportation, then the PCs have a lot more power at their finger tips. Compare that to a rigid Portal To The Past.