Here's what I think I'll use from now on. Roll 1d6 once every time:
- An hour passes,
- The party stops moving,
- There's a loud noise in the same area,
- The party does something that can attract a specific kind of nearby monster.
On 6+, a monster shows up. Roll on appropriate table, unless the action that triggered the roll is only detectable by a specific kind of monster: mind-magic or psi near psionic creatures, for example. Some things may adjust the roll (maybe torches should add +1, candles and burning oil are normal, dousing lights and removing boots and metal armor subtracts 1.)
If there's an extended loud noise (fight lasts 3+ rounds, for example,) the dungeon is on alert: roll every turn instead of every hour. On a roll of 1, the alert status returns to normal.
Some areas are always on alert.
The loud noise in the same area is a good one to bear in mind, more so when the characters are keeping quiet.
ReplyDeleteIt's also worth considering how a sound might travel, the clicks and clangs echoing down passages, and whether we modify a roll, or roll more dice, if the catchment area is wider.
And when players - sometimes improbably - start hammering at things, deep in spaces unknown but for their potential dangers, maybe every so many strikes...