Wandering monster checks frequency

[Falconer]

If my players try sleeping, healing, and sleeping again, they are guaranteed a random encounter!

[Benoist]

Yes, lots of sensible suggestions here. I assumed 1 check per turn as in OD&D rules, personally. I think the check-per-3-turns basis is a good base, because you can then either increase or decrease the frequency depending on specific areas (and movement of foes therein), activities of the party (as mentioned above), just hold on as suggested on page 9 of the DMG if warranted.

Sacrosanct, a user on the RPG Site, looked into a few of the modules and came up with this sample:

A1 Slave pits
Encounter occurs 1 in 6 (d6), check each turn

C1 Hidden Shrine
These monsters are encountered 1 chance in 12, check
each turn.

C2 Ghost Tower
Chance of encounter is 1 in 6

I1 Forbidden City
The chance for an encounter is 1 in 8, rolled every 3
turns.

I2 Tomb of the Lizard king
The DM should roll for random encounters six times per day: morning, noon, evening, night, midnight, and
pre-dawn. If the party has a planned encounter during the time period in question, no random encounter
will occur. A random encounter is indicated on a roll of 1 on d8.

S2 White Plume Mountain
1 in 12, every turn

S4 Lost Caverns
Daytime encounters occur whenever the
party stops in or passes through a hex with a dot (every 10 miles or so)

If the party is near a lettered encounter area and making
a great deal of noise, or merely waiting quietly for more than one turn,
there is a 1 in 6 chance that the monster nearby will come and
investigate -inside the dungeon

[thedungeondelver]

I go 1d6 per turn, 1 = encounter.

I also check after combat - did all that noise draw something else?

[Falconer]

I go 1d6 per turn, 1 = encounter.

I also check after combat - did all that noise draw something else?

Well, yeah, a combat automatically takes up at least a full turn, IIRC, so you’d have to.