Once again, the bloody-handed adventuring party has returned from the dungeon laden with gold and jewels. They spend the next few days carousing in all the local taverns, buying rounds of ale for the house and telling lurid tales of the monsters they slew and the strange magics they unearthed. Then, refreshed and ready for another go, they set out for the dungeon again.
Who else, having heard their tales and seen their gold, is heading into the same dungeon?
Roll 1d20 on the following table each week of game time. Assess an ad hoc penalty to the roll if adventurers have suffered heavy casualties and/or won little treasure of late, or add a bonus if adventurers have brought back a particularly rich haul or if multiple parties have been active in the area.
|1-12||No one else dares to enter the dungeon.|
|13||A band of local peasants ventures into the dungeon. Roll 1d6. (1: None of them are ever heard from again. 2: Too scared to enter the dungeon, they return with false tales of made-up adventures. 3: Finding only empty rooms, they wonder what the fuss was about. 4: After a nasty encounter with monsters, the survivors swear off adventuring. 5: As #4, but one or two survivors are willing to sign on with an adventuring party. 6: Clearing out 1d3 rooms on the first dungeon level, they find they have a knack for adventuring and form an first-level adventuring party.)|
|14-16||A low-level adventuring party enters the dungeon. Roll 1d6. (1: The party clears out 1d3 rooms before being killed off, leaving their bodies, equipment and wealth in the depths. 2-3: As #1, but some survive to tell the tale. 4-5: The party clears out 1d4 rooms in the upper part of the dungeon. 6: The party clears out 1d3 rooms in the middle part of the dungeon.)|
|17-18||A mid-level adventuring party enters the dungeon. Roll 1d8. (1: The party clears out 1d6 rooms before being killed off. 2-4: As #1, but some survive to tell the tale. 5: The party clears out 2d4 rooms in the upper part of the dungeon. 6-7: The party clears out 1d6 rooms in the middle part of the dungeon. 8: The party clears out 1d4 rooms in the lower part of the dungeon.)|
|19||A high-level adventuring party enters the dungeon. Roll 1d10. (1: The party clears out 1d8 rooms before being killed off. 2-4: As #1, but some survive to tell the tale. 5-7: The party clears out 2d6 rooms in the middle part of the dungeon. 8-10: The party clears out 1d6 rooms in the lower part of the dungeon.)|
|20||Another adventuring party is in the dungeon right now! Roll again, disregarding this result if you roll it a second time.|
|21+||More than one adventuring party has entered the dungeon! Roll again. Multiple results of 21+ are cumulative.|
Give each NPC adventuring party a name and roll them up on the appropriate tables; this way you’re ready in case they get in a fight with the PCs or if the PCs find and loot their corpses in a monster’s lair. When you roll that an adventuring party enters the dungeon, if a party of the appropriate level range has been inside before, there’s a 5 in 6 chance that it’s an existing party and a 1 in 6 chance that it’s a party new to the area.
When determining where the NPC adventurers go, roll randomly or choose as appropriate for the NPC party. Rival parties may stir up trouble with otherwise peaceful monsters, break useful devices and disrupt the dungeon ecology (if any). The PCs may want to ambush rival parties—and vice versa!