Natural threats in a mine

[Noldor Elf]

My group is very likely going to end up investigating an abandoned mine as part of an adventure. Smugglers are using a part of the mine as a storage, namely a former storage area that is located in the second layer of the mine and which can be reached through an elevator near the entrance of the mine.

That would leave me all the remaining mine with no purpose. The mine has been abandoned for couple of decades. The mine consist of three layers. Top layer includes basically entrance and two corridors which lead to the elevators. In the second layer there is storage areas and two corridors which were used for mining. Most of the deepest layer is cavern that was digged during the mining. Does that type of floorplan sound reasonable? (I have never been in a real mine)

What could be reasonable threats and problems that I could place to that remaining area? I have thought about making some of the structures old and weak, so that loud noises and area effects could cause ceiling to collapse partly or completely. There could be inhabitants, but they have to had tolerate the smugglers, so I don't know what could be suitable.

 

[Darklone]

Have a look at Old Ones storyhour... his CR 11 pit and some rats ...

Lorries are always funny. Water. Gas. Burrowing huge insects. Underdark monsters.

 

[diaglo]

elevator? was invented in 1853 by Otis.

pulley and lift is more what you should be thinking. not real safe. the ropes need maintenance or will break.

also water, gas, and possible fungi are great additions to a mine adventure.

look up diseases associated with spelunking on my website...www.cdc.gov

 

[Sam Witt]

That would leave me all the remaining mine with no purpose. The mine has been abandoned for couple of decades. The mine consist of three layers. Top layer includes basically entrance and two corridors which lead to the elevators. In the second layer there is storage areas and two corridors which were used for mining. Most of the deepest layer is cavern that was digged during the mining. Does that type of floorplan sound reasonable? (I have never been in a real mine)

Primitive mining would make lots and lots of short, narrow tunnels. The miners followed the veins where they could and carved out as little rock as possible while doing so. This means your lowest level should be short and cramped, very difficult to use anything but light or natural weapons and I'd cap everyone's Dexterity bonus at +2 to reflect the difficulty in moving around. Small creatures probably wouldn't have these penalties, giving kobolds and their ilk a huge advantage.

What could be reasonable threats and problems that I could place to that remaining area? I have thought about making some of the structures old and weak, so that loud noises and area effects could cause ceiling to collapse partly or completely. There could be inhabitants, but they have to had tolerate the smugglers, so I don't know what could be suitable.

Poisonous gases are a constant threat in mines. These tend to gather in pockets, so you're going down a corridor and where it dips or rises, the air is suddenly poisonous. Anyone with a torch will probably notice it flicker (give 'em a Spot check (DC 15)) as the air quality drops within 10 feet of the gas pocket. Most of these gases will do Con damage of some sort, adjust the save and lethality for the resources of your party.

Flammable gases are dangerous, as well and collect in much the same way. Use the same Spot check for folks to notice their torch suddenly burning brighter and faster as the trace amounts of fuel in the area begin to burn. Those who proceed into the pocket of flammable gas with burning torches should expect an explosion - probably 5d6 or so, with a Reflex save for half.

Those who enter without a torch still have the problem of not being able to breathe - again, treat it as poisonous gas with varying Con damage based on the strength of your party.

Water is a hazard in mines, as well. Have a weakened section of tunnel with water dripping from the ceiling - any fighting in here could collapse the ceiling and flood one level of the mine.

As you noted, deadfalls and cave-ins are a serious danger in an abandoned mine and, if it's a wet mine, rotting support timbers will be ready to give way at any moment.

If I were doing this, I'd have one narrow section of the bottom level flooded and then have some amphibious creatures on the other side. They haven't bothered the bandits, because the creatures never go out into the upper parts of the mine. Have an entrance to the underdark to explain how they eat and whatnot.

Then, have one or more bandits flee down into the bottom level of the tunnel and swim through the submerged part looking for an escape route. He irritates the monsters, who come out to see what all the ruckus is .. .

 

[Piratecat]

elevator? was invented in 1853 by Otis.

pulley and lift is more what you should be thinking. not real safe. the ropes need maintenance or will break.

Diaglo's a genius. They get on the lift and start down, and the ropes snap - sending them hurtling down to the lowest level of the mine. Now they have to get back up AND find their goal, all while being stalked by something in the dark....

 

[Altalazar]

Gas, fresh air, water, and collapse. Those are the three main problems, sometimes interrelated.

If you really want to get a good feel for a mine without actually going into one, go to the Chicago musuem of Science and Industry - they have a coal mine you can go down into (obviously not a real one) that you take the elevator down - then you see demos of the gas detectors of various stripes they've used over the years - from most primitive (which you'd be interested in) to most modern - and the same with mining equipment and the techniques used to secure the ceiling.

I wonder now what magical methods would be used for mining. I can think of a few - fresh air from spells (also fixing the gas problem) - magical light sources (that are therefore not flamable - also gas issues) - walls of force made permanent that are used to hold up ceilings.

 

[Darklone]

... Click... Click... Click...

 

[Azlan]

Poisonous gases are a constant threat in mines. These tend to gather in pockets, so you're going down a corridor and where it dips or rises, the air is suddenly poisonous. Anyone with a torch will probably notice it flicker (give 'em a Spot check (DC 15)) as the air quality drops within 10 feet of the gas pocket. Most of these gases will do Con damage of some sort, adjust the save and lethality for the resources of your party.

Will torches really flicker when the party, say, enters a pocket of air heavy with carbon monoxide? Didn't miners used to take canaries in cages down into the mines with them, for early detection of carbon monoxide?

Flammable gases are dangerous, as well and collect in much the same way. Use the same Spot check for folks to notice their torch suddenly burning brighter and faster as the trace amounts of fuel in the area begin to burn. Those who proceed into the pocket of flammable gas with burning torches should expect an explosion - probably 5d6 or so, with a Reflex save for half.

I would think that by the time torches begin flaring brightly, that it's too late -- the group is already in an area rich with flammable gas, and an explosion will result. Perhaps blue caps on the tips of torch flames would be a more realistic early warning?

I dunno... I'm just wondering aloud, here. I'm certainly no expert on the matter.

 

[adwyn]

The most dangerous aspect of any hardrock mine is actually hypothermia. As a general rule of thumb mines will be around 45 degrees F, but exposure to outside air flows can leave them colder, even below freezing in northern climes. If they are deep enough they begin to warm up, but at the normal 45 temperature hypothermia can set in quietly, especially if anyone is wounded.

Most mines are not actually level. The slopes can range from nearly flat to quite steep; 60 degrees is the steepest I've seen and it required harnesses for the miners.

Cave ins are not that common, but erosion resulting from exposure to air can cause the roof of a mine to "slag offf" large rocks, often in long thin sheets - likely to be fatal for anyone caught beneath.

As mentioned water is a constant threat. Ground water can destabilize structures, rot out support timbers, and of course flood. The water found in old mines is rarely safe to drink, usually it is toxic - won't likely kill you with one drink but exposure is bad.

Probably too modern for you, but in North America one constant danger in old mines is left over dynamite. The nitroglycerine seeps out over time and may become inert or remain dangerous. Either way any indication of old storage boxes or crystallized nitro makes for a hasty exit.

 

[WampusCat43]

I had a pair of gricks that lived in an interior room only accessible by a 3'-wide hole down at floor level. In your case, the bandits may not have wandered by the hole yet, or the gricks didn't notice them when they did.
For some bizarre reason, both groups that I ran through this sent their wizard into the hole first

Be aware that these critters have DR 10/magic, so you would need magic weapons or a Magic Weapon spell to do much good against them.

Other items I had lying around were broken picks, overturned carts, small streams of water, odd air currents, and rude graffiti (in gnomish) on the walls.

There are a lot of good cavern tiles around also.