plot devices to drive time pressure

[Spiritchaser]

Part way through my next gaming session the PCs (level 3) are going to enter a cavern complex at the source of a river. The cavern is infested with low intelligence monstrosities, which the PCs may eventually learn were deliberately placed there.

From a metaplot point of view, the PCs need to learn how dangerous infestations of this sort are, that regular imperial forces are increasingly distracted by... Something to the south, and how vulnerable the population is without the legions. This is all in hand.

I also want to add something extra to the dungeon crawl part

I think a panicked, clear them out fast and escape fast or else would be great.

Does anyone have any suggestions on how to capture this feeling?

[CursedRhubarb]

Have the creatures themselves be rather weak and kinda pathetic but numerous so the PCs start off wondering what the big deal is with them and start thinking along the lines of "Yeah there's a lot of them but a blind hobbled farmer could fight off a hundred of these!"
Then they come across a room where the creatures food supply is. This would be something like stolen farmer carts/baskets loaded with all kinds of food even the most poor village has...along with a dead farmer.
In this room they witness creatures feeding on the food and farmer. Ones that have eaten become stronger, bigger, start to mutate into more monstrous appearances and go from "sense at and they die" to "oh god it just thew the barbarian across the cavern and shrugged off a max damage crit like nothing."
From here they learn to be wary of any that have eaten and what could happen if just one makes it to a village.
Then they find the "nursery". A giant cavern that a dragon would find spacious and every inch of the walls, ceiling, support pillars, and most of the ground area that is covered in eggs. Enough that if all hatch the creatures would outnumber even the kingdoms armies by 10 to 1 and they only thing to prevent them from hatching and feeding on the villages are them...they just need to find a way to get rid of them and handle the many that have already fed....oh and the queen.

[gfishfunk]

Some ideas:

1. Dungeon Something: The creatures are generally weak but know how to create interesting traps. They begin flooding the main entrance after the party gets several rooms in (but are still able to see the entrance). A slab goes down, obviously controlled by somewhere else, and then water starts pouring in.

2. An Unknown Threat: several patrols, and even one decently large contingent have disappeared to the South but within the kingdom. Each group was on route to the Southern Outpost, but disappeared before arriving. Not slain, not lost - disappeared entirely. No one is panicked yet - and that is odd to the players because that should be sending off alarms. The government knows that there is a roving entrance to the Feywilds that drifts about, and they are investigating that at the moment. This happened some years back, and the patrols and the contingent know how to survive in such circumstances. However, unbeknownst to anyone, that is not what did it this time.

[smcmike]

Ticking clock plot devices:

- some sort of parasite or illness that afflicts one PC. The party has reason to believe the key to curing him is in the cave.

- same, but some other victim - perhaps the whole village.

- the goal is a missing person or a hostage that doesn't have long to live. This is enhanced if the players know that the hostage doesn't have long, somehow, such as they somehow got a message out.

- something that cuts off retreat and progressively pushes the party through the dungeon. Collapsing tunnels work, but are a bit arbitrary. An unbeatable horde can work, if you give the players clear warning and chances to temporarily block their pursuers. It's also fun to play with progressively flooding tunnels, which are less arbitrary than collapse.

- endless drips of enemies, that can build into a lethal horde and prevent players from resting.

[Aembrosia]

We've got to collapse the stalactyle support structures of the cavern!

Rocks fall the party dies.

But they saved the kingdom.

[Biggstick]

Have the creatures themselves be rather weak and kinda pathetic but numerous so the PCs start off wondering what the big deal is with them and start thinking along the lines of "Yeah there's a lot of them but a blind hobbled farmer could fight off a hundred of these!"
Then they come across a room where the creatures food supply is. This would be something like stolen farmer carts/baskets loaded with all kinds of food even the most poor village has...along with a dead farmer.
In this room they witness creatures feeding on the food and farmer. Ones that have eaten become stronger, bigger, start to mutate into more monstrous appearances and go from "sense at and they die" to "oh god it just thew the barbarian across the cavern and shrugged off a max damage crit like nothing."
From here they learn to be wary of any that have eaten and what could happen if just one makes it to a village.
Then they find the "nursery". A giant cavern that a dragon would find spacious and every inch of the walls, ceiling, support pillars, and most of the ground area that is covered in eggs. Enough that if all hatch the creatures would outnumber even the kingdoms armies by 10 to 1 and they only thing to prevent them from hatching and feeding on the villages are them...they just need to find a way to get rid of them and handle the many that have already fed....oh and the queen.

I really like this idea and would definitely consider something along it's lines. As someone who has never DM'ed, one thing I can tell you that I hate is railroading. Do you know what collapsing caverns, flooding that prevents backward movement, or a stone wall that prevents escape through the massive cave system we've just entered does to me? It makes me look for ways to get this train car off of it's pre-established track. This of course only happens if a DM doesn't give me or the group a choice in what we're doing and how we're going about doing it. Give the players a compelling reason to dig deeper into the cave and you won't need any of that.

So what you want is for the players to clear the cavern quickly, escape quickly, and find out some pretty specific information about the things that exist in this cave. My question would be have the PC's already entered said cave? Are they just inside the entrance? Have they done any research on said caverns? For the sake of somewhere to start, I'm going to assume they haven't entered yet. Perhaps right as they're about to enter said cave, they run into a strange sort of NPC. This NPC could be a Ranger, a woodsman, a hunter, a spelunker, a miner, or really anyone that has a slight reason to be out and about near this set of caverns. An old miner who speaks such an accented common that the party can barely understand him might be interesting. Maybe he has a partner, or something valuable that was taken from him during the night, and it was taken deep into "Dem der caves!!" If it was a partner, maybe the old miner provides some foreboding information about creatures that reside in said cave, but that he'd offer part of the loot stolen if they could save his friend's life. If they manage to bring the friend (alive) or loot (still in one piece, or all the pieces) back before a certain time, he'll give the party a larger reward. If they bring the friend (dead) or loot (broken, or some of the pieces) back, maybe they only get 1/10 the promised reward.

While the party treks through this cave system, they come across these nasty monstrosities, dispatching them quickly. When they finally make it to the final room, there is the friend/loot about to be eaten/destroyed by something much more clever then the dumb brutes they've been slaying in the caverns. It could be cheesy like a Bond villain, or just something that is slightly above what the group has come to expect. Whatever is about to kill or destroy the friend/loot is something that could be turned into a sort of recurring side villain for the party. Give the villain a way to escape after s/he monologues about some grand scheme to take the monstrosities that inhabit the caverns and turning them on the rest of the countryside.

It might not necessarily be important to your story, but it establishes a rival for your party that they may decide needs to be dealt with. Having someone's life (or size of reward) on the line tends to make most groups try and move a bit faster when moving through a dungeon.

[Spiritchaser]

a progressive flood could work here. Its a bit arbitrary, but if the creatures have dragged a bunch of villagers into the depths of the cave to lay their eggs in... Rescue the villagers before everyone drowns could work...

Not a flood that blocks off areas, but one that simply fills the caverns from the ground up...

The PCs have encountered these things before, they're about CR 1-2 for the adults, and are very keen on hiding in slimy walls to pounce. (+5 stealth) they havnt met an alpha yet... I'll have to find a way to surround a CR 3 with some CR 1/4:-! 0 broodlings that doesn't murder the party

[Segev]

The beleaguered imperial forces have put a bounty on the ears of these monstrosities. There is another party racing your PCs for to maximize the bounty they collect.

The monstrosities attack through the river, which is rising towards their cave. Kill them before they escape and become more dangerous.

The farmer that is suggested as a horror-meal has been kidnapped and the PCs want to find him before that happens.

It's been discovered that the raids in increasing numbers by these monsters are due to their egg-laying habits...and each generation has been geometrically larger than the last. Find them before the next one hatches with you in the cave. Don't let any survive to lay more.

[smcmike]

Railroading doesn't bother me if it's well done, but that's a matter of taste.

Flooding is better than rocks because it is easier to give the players some firm knowledge to make decisions. They need something from the dungeon, and the water is rising, but slowly. So long as they don't try to rest, they will probably be fine, though on the way out they may have to do some wading or swimming.

It also provides tactical challenges. Fighting things while wading is a nightmare.

[gfishfunk]

I usually get rid of railroading by providing multiple routes and multiple objectives; bonus points if they are mutually exclusive.

1. One of the routes out of the main cavern is where the creatures are actively retreating to; there is definitely a second exit that way.
2. There seems to be a route that would lead to the mechanical apparatus that is causing the flooding (irreversible) and closing the door (reversible).
3. There are screams from another tunnel (opposite the one leading to the mechanical apparatus), human sounding screams. And some of the water is flowing that direction.

The players can do two of the three things at most with a timer set up. If they come up with a creative way out of the main room, that works too. This is not railroading at this point, its surviving a bad situation based and allows the players to make meaningful choices.