Alas, I cannot find my submission in the works even though I did send it in in due time. Well, here goes. The wish I was assigned was:
A handful of clever tricks to place in dungeons when the party goes down that hallway or staircase I forgot to plan out. I can always use more tricks.
First of all, and this is not a trick: Ask the players to talk amongst themselves while you figure out how to proceed. This is almost always better than adlibbing from the cuff, because even good adlibbing is based on preparation and understanding of the situation at hand. Also, I'm bad at tricks, so here are a handful of options that help you with the adlibbing:
→ mirror the current dungeon level, everything the characters do here counts in reverse for the original level. I.e., all treasure collected gets removed from the pre-original-level values, monsters that get reslain will be alive again in the original level (AND REMEMBER THEY WERE KILLED TWICE BY THE SAME PEOPLE). All stairs are inverted of course, so if you go down, you will end up one level above the original one, if you go up, you will end up in another random level.
→ The group found a back exit that was hitherto unknown! Depending on the landscape surrounding the dungeon, this can be 1) a steep cliff, 2) an underground stretch of a nearby river, 3) a forgotten mineshaft, 4) a known mineshaft complete with workers and machinery, 5) an undercity of a lost civilization, 6) the lower donjons of an evil lord's castle. There's a fake wall that covers up the dungeon exit from the outer side, but from the inside it's clear this is just a cleverly painted drape or something like this.
→ Add all the usually omitted institutions that are missing in a dungeon like food areas, rest rooms, etc. make them all communal areas that have a lot of off-shift dungeon inhabitants around that will file complaints with the guild if they're made to fight against outsiders during their time off.
→ The hallway/staircase is just long enough to get you out of darkvision and torch light radius, so it's a perfect place for schmoozing -- roll twice on the encounter table (or pick two unlikely but equally enamored options) to figure out who Romeo and Juliet are. If this is too one dimensional, roll on the reaction table to see whether this is an extortion racket, some shady business, or true love after all.
→ The players found the BBEG's backup centre of operations. It's probably mothballed and covered in dust, but this is where you can drop hints about the background if you're into that, or some scrying devices that show random parts of the dungeon if this is the BBEG's lair (but then why don't you know where this hallway goes to?)
→ If the GM doesn't know what's in this hallway/at the end of this stairway, probably no-one in the dungeon will, and won't care about this place. The group found a perfect quiet place to rest and recover! You done goofed by not being prepared, let the players reap the reward.
→ Sometimes a dead end is a dead end. Someone planned on extending the underground lair, but work was not finished. Maybe the workers are on strike?
→ Make the hallway end up in a portal. If you don't know what kind of portal or where it leads, consult the Kefitzah Haderech or, if you're a collector of GURPS supplements, pull one at random from your shelf. That's where the players are now. If you have a National Geographic subscription, take the words on the spines of two consecutive issues and make up something based on that.
→ Here's where you find a 1
- magical pool,
- forgotten altar (good deity)
- illicit shrine (evil deity)
- magic mouth mocking whoever triggers it with long forgotten insults
- magical statue
- magical mirror.
→ The hallway ends in a gelatinous cube that has permanent darkness cast on it.
→ Have something funky and out of place here. Wedding chapel with Elvis impersonator, two goblins manning a soda stand, a powered-down steel golem, a rack of poisoned lasguns … you forgot to plan out; embrace that moment and whack your own expectations on the head.
→ The latest feature of the dungeon that the players discussed? That's now here. If they discussed this hallway, they're trapped in an infinite hallway and need to find a way out. If this is too quantum-ogrish for you, consider being prepped better next time!
Go and pick a handful of one page dungeons. Read them twice each. Whenever you reach a place where you weren't prepared enough, plug in one of these. When you're down to three, pick two new ones to fill your stack.