When refereeing OSR sandbox game (using whatever rules; key parts are player-driven sandbox play with neutral referee, and rules as negotiable representation of fiction) I use random encounters: typically, wandering monsters (or other random events) happen with 1/6 chance per location-dependent time interval; maybe once per ten minutes, maybe only thrice a day.
When rolling d6:
- Random encounter.
- 2-3. Tracks, signs, howls in the distance, or other such hints of a wandering monster. Alternatively, a dragon flying high in the sky or some other voluntary encounter.
- 4-6. Nothing.
The only problem is that I often forget to use the result 2-3, and instead roll a random encounter on a result of 1 and have nothing happen on the other results. This reduces the amount of information players have on their environment and makes the environment less of a real place, thus making play both harder and less interesting.
How can I remember to add tracks and such when checking for random monsters? Alternatively, is there a rules mechanic with similar effects that is less easy to forget to use in midst of play?
Please answer from experience, yours or reported somewhere.