The nature of the random encounter check is that of a timer. While it is not a literal countdown (since random results are mathematically independent), it simulates one. It is the danger clock, always ticking, giving meaning to the decision to search (or not), investigate just one more room (or not), or engage in any other potentially fruitful exploration activity.
There are a number of dynamics within the game that seem structurally similar to the periodic encounter check. Randomizing when light sources expire has also been suggested in several different places. Many systems as written specify that PCs should rest every sixth turn (though I have never once seen this in practice). Torchbearer imposes conditions on characters as turns pass to represent exhaustion and the abstract effects of other dungeon hazards. John B. suggests sometimes interpreting a random encounter as a monster spoor rather than an actual encounter.
Why not put all these things together systematically? Consider the following rule:
When the party moves into a new area or spends time on an exploration activity, roll the encounter die and interpret the results as follows.
- Percept (clue, spoor)
- Locality (context-dependent timer)
- Exhaustion (rest or take penalties)
One might object: does this not lead to absurd results such as torches going out on the first turn or PCs needing to rest on the second turn? Well, yes, but you are an intelligent human, so ignore results that do not make sense. A result should be interpreted as not “X happens,” but rather as a prompt. A result can be deferred, but only so many times. The weight will naturally build up in the back of your mind as events proceed. As a guideline, ignore results above 3 for the first 6 or so turns.
You could have a general “light source” entry and just pick one light source randomly each time (this has the advantage of not having all torches go out at once), but I prefer to distinguish between the two main types of light sources given their differentiation on the equipment list. Conceptually, I think it helps to have different spaces in your short term memory for each, as you can have the sense that 5 has come up several times already and know that is relevant for lanterns. Torches should probably go out almost every time a 6 six comes up and lanterns should deplete approximately every third or fourth result of 5.
“Locality” is meant to be used for area-specific state that should be kept separate from standard random encounters. Examples: water rising, the stalker drawing nearer, a prisoner loosing an appendage to the torturer, doors locking behind PCs, and so forth. The possibilities are limitless and make every location potentially mechanically different in a way that is player-salient.
In addition to streamlining gameplay and decreasing intrasession bookkeeping, such a procedure also decreases null (“whiff”) results. Almost every turn result means something. This may or may not always be a good thing. Maybe there is something to be said for not having something happen on every roll. However, given how dungeon exploration tends to play out in real (player) time, I suspect this is about right.
The results table could be replaced with a custom one for a given location, but the above spread seems like a reasonable default to me.
See also: a method of play.