- Intangible Time Travel is probably the best method, since it lets you observe freely, without affecting the era you are observing.
- Videocassette Time Travel would work well for Time Spying as well, especially if it's Intangible VCR Time Travel. In fact, that combination is even better than mere intangible time travel, as you have a frame of reference to start from, being able to shadow someone through time, rather than having to guess where and when they'll be.
- Mental Time Travel is very useful if you're spying on yourself, or on someone likely to trust your younger self (or likely to ignore "the neighborhood kids"). Of course, it's also a can of worms, as the experience of being a childhood spy might mess up your childhood pretty heavily. All depends on what the laws of Time Travel are in your setting. On the plus side, it's very hard to detect. Even if caught red-handed, there's some chance they'll let you go because "he's just a kid, what harm can he do?"
*Branching Timelines have their own uses. A time spy whose cover is blown in one reality can go back and try again, or a time spy might be able to get information about the different ways an event might happen before trying to prevent it.
If none of those specialized forms of Time Travel are available, then you still have at least three options/methods:
- Microsecond Time Spying. - The time machine consists of a high-speed camera (or sensor suite), and an instant recall program. You send it to the moment you want to observe, where it manifests for just a fraction of a second, records one image, and returns. Unless time travel in your setting is a messy laser-light show, it probably won't be noticed beyond a "did you see something?" The camera/time machine returns, you look at the picture, and if that doesn't give you the info you needed, you resend it to a different moment. You can't really pick up sound this way, or video/motion, as either would require the camera being there for longer stretch of time, but light travels quickly enough that you can shoot constant snapshots (provided a camera that can handle very low light exposures). Variations could involve a manned version, or a machine that jumps constantly and visits hundreds of moments before returning to base with photos.
- Traditional Time Spying. - The old fashioned spy methods, just augmented by a little time travel. You get to spy on your target round the clock, by using your time machine to sleep elsewhen. When you start getting tired, your elder self shows up to take over, and you hop off to the temporal safehouse to catch some zzz's before coming back to relieve yourself. Should your target notice you, you can have a fool-proof cover identity set up - being able to go back 30 years or so to fake a birth certificate and any other documents needed to sell your cover. If things go poorly, you just vanish into thin time.
- Future Google - You hop up and down the timeline, checking in with various databases, history books, and mutual friends, to assemble significant information about the target without ever having to be in the same room as them.
Some of these ideas were influenced by the Continuum RPG, but the majority of it was just a logic exercise in brainstorming how a time machine would impact surveillance and espionage. If you see holes in this, or have cool ideas of your own, please add them.
Game and Story Use
- PCs might use these methods to track a foe or figure out the big mystery the GM presented them with.
- Throughout the campaign, the GM keeps having the PCs make rolls of "awareness" or "spot hidden" or whatever similar skill your game uses. When successful, the GM just says "You thought you saw something out of the corner of your eye, but it's gone now." Not until they accumulate a large number of successes, or penetrate the enemy lair, do they learn that the Big Bad Evil Guy has been using Microsecond Time Spying on them ever since the scenario started.