[HR] Mining Rules

I like mining. I found my copy of the Complete Book of Dwarves and decided to make up some mining rules for ACKS.

They are fairly long and have a lot of tables. I’ll provide a summary here, but for the full thing, I set up a quick wiki page just so I would have somewhere to post tables, and you can read it here: http://aryxymaraki.pbworks.com/w/page/76091609/Mining

Also available as a download on the Downloads page on this site: http://autarch.co/downloads (in the Supplemental Rules section)

For summary, I have rules for finding mineral veins in a hex, then accessing them, then extracting ore, then smelting it.

Mines come in various flavors (copper, tin, lead, iron, silver, electrum, gold, platinum, mithril). The first four listed there are common metals, the last five are precious metals. Each has a varying amount of ore that you can extract per week of work (I used weeks because Complete Book of Dwarves does, but you can easily translate it to months by just multiplying by 4).

Each mine has a quality rating (1-10, or 10% to 100%) which is the percentage of its ore that is metal. Once you smelt your ore, you end up with metal equal to ore weight * quality. Once you know your metal weight, you move over to simply using the mercantile system; 100 stone of common metals is a load, 4 stone of precious metals is a load.

Smelting it requires you to buy a smelter (which come in three sizes, each of which can handle varying amounts of ore per week) and pay for the operation of the smelter (which is much more expensive for precious metals than for common metals).

Mines have a duration before they run empty and you have gotten all the ore. There are also some tables I stole from CBOD to determine which direction the vein goes, so you can properly describe your underground adventures as you accidentally break into a cavern full of lava and screaming.

If you like fun numbers like “Minimum Quality for Profit” and “What happens if you hire umber hulks to mine for you”, there’s a link to the Mining Math page on top of the Mining page. The Mining page is written to be read, the Mining Math page is more me doing random math then posting it.

I see no mention of a random chance of digging too deeply and too greedily :stuck_out_tongue:

The forums need a +1 button.

I also +1 this. Maybe a “Vagaries of Mining” table, modified by total depth mined. Or, more correctly, modify the Mortal Wounds table so the deeper you are the worse it gets.

Kinda want to look and see what Dwarf Fortress does now.

Dwarf Fortress has three successive cavern layers, each more dangerous than the last but usually not enough to end a well-prepared fortress on their own. Particular species of monsters are native to each cavern layer, though I forget which ones are native where (it’s been a while). Cave trolls, giant cave birds or bats, giant cave spiders, beastmen, cave dragons, and gremlins can pose significant danger to a poorly-defended fortress, while giant salamanders, cave crocodiles, pond grabbers, and some of the larger herbivores are often responsible for casualties among civilians involved in economic activities in the caverns. The real danger from the caverns is Forgotten Beasts, which are randomly generated megafauna with special abilities like plague dust who appear intermittently. It’s not unusual to have a fortress ended by a flying forgotten beast whose body is comprised of a hard material like stone or metal, or one with a particularly deadly syndrome. Finally, there’s hell, reachable by mining into the pillars of adamantine ore protruding out of the Great Magma Sea at the bottom of the map. Breaching hell brings forth a torrent of demons, each as dangerous of as forgotten beast, and is almost guaranteed to bring a fortress to ruin unless measures have been taken to seal the passage out before the breach is made.

That’s what encounter tables are for! :stuck_out_tongue:

Good point though, there should be mention of random encounters. Off the top of my head, I say guarantee at least one random encounter when surveying a non-pacified hex (roll for a normal chance of wandering monsters if the hex is pacified), and roll for a random encounter as appropriate for terrain type every 20 feet of tunnel length (every time you roll on the Vein Alteration table).

The deeper you are, the more terrifying the encounter table should be, and the more likely an encounter should be.

I threw together some depth rules real quick.

In general, now, the deeper you are the better your vein will be (both in metal type and in quality). Random encounter check every 20 feet of excavation. Random encounters when surveying.

So…since I started looking at this more in depth:

Does that imply that at the start of the mine, you’re hitting the vein in mid-stride, and it goes in two directions from the starting point?

And irregardless of the answer to the above, if the 1d10 direction roll comes up that the vein ends, that takes precedence over any other duration roll?

(presumably a kind Judge would allow the player to find another vein of the mine if they were lucky enough to get a millenia mine, or they’d just wallow in the tears of the player, either or…)

Yes to both.

Note that the duration applies to work in both directions, though. So if you have a mine with a duration of 30 miner-weeks, and you mine it for 20 miner-weeks in one direction before the vein ends, then go back in the other direction, you only have a total of 10 more miner-weeks of work before the vein is played out.

If the Judge prefers (since this will result in a lot of mines running out of ore before their duration is up; a 10% chance to end per 10 weeks of work, with only one second chance, makes it pretty difficult to have a Mithril Hall-style vein), the vein can simply continue in a different direction when you roll Vein Ends. Roll again on the direction table to find the direction of the connection.

Personally, I think I’d be likely to run it with direction change for any vein with a duration of years or better, and let the vein just end for one with a duration of weeks or months.


I’ll work up an automated design as I’m able; and see if I can get some interesting results out of it.

These rules are marvelous! One thing, though: I'm inclined to employ slaves to work my mine instead of free miners, because I am a horrible person. Or maybe I'll just research a spell that summons spectral miners from dwarf heaven and forces them to work. Either way, I should be able to drastically cut down on my labour costs - but do I still have to pay for shoring timbers? And if so, how much?

I guess my question's a subset of the broader one of whether you have to pay for the materials used by a slave artisan. Maybe I should've posted this in Ask the Autarchs, instead...

Suppose I'm surveying in a hex that's been civilised for some time. Should I assume that some or all of the minerals have already been mined out? Or does the tendency of surface veins to be less profitable ones already take that into account?

It would certainly reduce your labor costs!

You would end up just having to pay for the supply costs of the slaves, instead of having to actually pay them for their work. The supply costs for slaves of various races can be found in Domains at War (I could look it up in theory :P)

Domains at War also has the rules for raw materials in construction projects. If I had written this after Domains at War came out, instead of before, it would probably have more explicit references to it and more direct linkages. However, nonetheless, the same concepts can be used. (If I recall correctly, materials accounts for half of the cost of a construction project, but I haven’t looked that up and might be wrong.)

An Age of Civilization modifier to the rolled number of veins in a hex would certainly be appropriate. The categories in the Demand Modifiers section of ACKS are 0-20, 21-100, 101-1000, 1001-2000, 2001+; applying a -1 to the die roll for veins for each age category beyond the first (so a modifier of 0 to -4) would be a simple way to do it, off the top of my head. If the area has been heavily mined historically, a modifier of -2 per category might be appropriate instead. In the end, though, the number of veins available is up to the Judge’s discretion; the dice range is offered as a guide and for an ‘I have no idea, let’s see what the dice say’ option.

[quote="Aryxymaraki"] Personally, I think I'd be likely to run it with direction change for any vein with a duration of years or better, and let the vein just end for one with a duration of weeks or months. [/quote]
Hmm. I'd probably houserule the second and subsequent "vein ends" results rolled would reduce the remaining duration by a random number of miner-weeks. I'd decide exactly how many miner-weeks by following the same rolling process used to determine the duration of the vein in the first place: Rolling d% and re-rolling for larger increments of time on doubles. This would mean that, yes, a "vein ends" result will usually end a mine that's only got weeks or months left, and that massive veins will almost certainly remain around for a much longer period of time - but that there's never a guarantee that the mine won't dry up unexpectedly.

Alternatively, I guess I could just say that a mine isn't completely exhausted until it recieves a number of "vein ends" results based on its original duration - say, 1 result per 100 miner-weeks or part thereof. This would make massive veins a little more bulletproof, and could perhaps be explained as your estimation of the remaining ore reserve growing more accurate as you dig more of it out.

my small contribution to this thread: costs of materials is considered to be 25% of the total construction project