There are many ways of using divination magic, each with their advantages and disadvantages. This entry and the next will look at two of the extremes: the very narrow (path-walking) and the very broad (precognition).
Path-walking is generally considered to be the second-longest-ranged ability available to diviners. It’s also one of the most difficult, and requires an extremely delicate touch.
Path-walking can be best described as stringing together a very long chain of if-then conditions. Normal divination just looks at a single possibility: if I open that door, what happens next? Path-walking keeps going: it looks at what would happen if you open the door, then walk down the corridor, then turn left, then open the door at the end, then look along the shelves, and so on. It’s a lot like assembling a chain one link at a time.
The main disadvantage to path-walking is that it only works as long as every link in the chain is formed out of a predictable event. Any significant concentration of chaos or unpredictability is an impenetrable barrier: you can path-walk up to an unpredictable part of the future, but you can’t path-walk beyond it. It would be like crafting the next link out of sand: as soon as you put any weight on it it would collapse. This is why a diviner can see up to unpredictable situations, but can’t see beyond them in any kind of detail.
The length of time into the future that a diviner can path-walk is limited by the diviner’s skill and by the total uncertainty of all the links in the chain. Even if each link is mostly predictable, the total uncertainty will eventually accumulate to the point where no further information can be gathered: it’s like building a tower out of uneven blocks. Small imperfections in the construction multiply until the whole thing falls apart.
(The observant reader will note that for this reason, path-walking is largely useless if the diviner is in an unpredictable situation already. There’s no way to build a chain since you can’t get a stable first link.)
Clarity of Vision
The best way for a diviner to minimise the limitations of path-walking is to place themselves in a highly predictable and stable environment. Out in a busy street, a path-walking diviner would be lucky to see a few minutes ahead: in the middle of a crowd they’d be lucky to see a few seconds. But if they’re alone in a house then there’s very little to disturb them. A room with a closed door and windows is a very stable environment: you can leave it for months without any significant change. It’s not timeless, of course – nothing in life is – but the changes are very, very small, enough to make an exceptionally good divining platform. In situations like this, a diviner can predict quite long chains of events with extremely high accuracy, so long as they don’t go beyond the static area.
Despite the obvious problems, path-walking has some application to conversation. A diviner can’t predict the entirety of an interaction with another human being (not unless the person in question is so set in their ways that they make a plant look responsive) but they can get a decent prediction of the first thing the person is likely to do. So a diviner can figure out, for instance, which of a series of conversational openers is likely to work best, so long as the target’s reaction to those openers would be immediately obvious.
A diviner who’s really good can continue using the same technique during a conversation, constantly looking ahead to observe the futures as they shift with each exchange. This is much like driving your car through city streets at rush hour while simultaneously navigating on a GPS phone which keeps updating every few seconds. Still, it’s a handy trick, so long as you don’t mind the occasional crash.