I had some spare time, so here's Chalicier's Guide To Playing Underhive Settlement Mod:
- If you want to be able to dig deep, choose a biome with "little soil".
- The easiest way to get access to mineral resources is either to dig deep as above, or include some Mountain biome in your embark zone. (The latter is especially useful.)
- While Hivers like the outdoors much more than Dwarves, you can't stay in the open air forever. Those damn dust clouds will mess everything up. Get some shelter sorted.
- Bring some animals along. You can probably afford a couple of grox cows and a grox bull. While you'll probably never produce enough meat that way, the milk is a BIG help and grox are also rather excellent fighters, so if you can manage to pasture them near your main entrance you're laughing. Sligs grow quickly, so they're a good choice for a meat farm, but produce no milk and can't fight. Dogs are handy, but most Underhive fauna will splatter a dog in a second.
- If you're using my fixes, things that kill vermin are a major source of food via Ratburgers.
- Your embark MUST include a crate of bottles, a power cell crate and a toolkit. You cannot survive long without a Water Still.
- Other things that are handy in an embark: Another toolkit, rockcrete (for flux - many biomes will have none and steel is important), wood (it's rare in the Underhive even in "wooded" zones), grave cotton seeds (not just clothes but you need Grave Cotton Cloth to make gunpowder), bitter moss (a handy source of quick food), extra barrels, and lots of junk piles (for a random burst of useful tools and trade goods).
- A shotgun case and a shotshell case are also useful if you plan on hunting. While most Underhive fauna is edible (Hivers will eat pretty much anything), most of it will take more than a crossbow to kill. Once you've unpacked it, go into the (M)ilitary screen, select (A)mmunition and then set the Hunters section to use shotshells instead of crossbow bolts. Your hunters will then pick up the shotgun and ammo and go hunt some beasties. Be prepared to lose a hunter or two - Underhive fauna are very, very dangerous.
- First thing to do on embark is to build a Receiving Bay to unpack your various crates. Next thing is to build a Water Still with the unpacked Power Cell and bottles. You'll need a Water Filling Area too. Finally, you'll need barrels to put the water in. Consider putting a limit on barrels in your main food stockpile so as to reserve some for water.
- Don't assume you can skip the water distilling if you have a water source on the map. Underhive water is Bad News. Unfortunately you can't stop your Hivers giving it to the wounded, but try not to let them drink it.
- There's a nasty DF bug involving bottles and other tools in bins. Sometimes they get stuck in them and refuse to come out. Tools are less important in vanilla DF but critical in the Underhive. I get around this by making a special Tool stockpile which does not allow bins and disallowing tools from my normal Finished Goods stockpiles.
- The Hiver Forge makes weapons and gun components, the Craftsman Forge makes everything else metal.
- You need a LOT of fuel for most industries in Underhive Settlement. More in fact than most embarks will easily support. Don't neglect the Breaker Station and, if you get the schematics, Separator.
- Making flak or carapace armour is very difficult and labour- and material-intensive. Strongly consider studded leather armour; it's not magnificent, but it's definitely better than nothing.
- Nearly everything you want for your advanced industries requires chemicals from the Elecrrolytic Shrine and Alchymical Workshop. You will need Large Steel Drums for the former, and 3 glass vials to make the latter. Luckily, "dirty sand" zones are pretty much everywhere.
- You need lots of potash for things, and you do not have much wood. Good thing you can reduce vermin and animal parts to ash in the Kiln...
- For ammo, you'll need priming compound (made in the Alchemy Lab from Various Stuff), gunpowder (made in the Alchemy Lab from Grave Cotton Thread), Brass for the shells (made from Cuprum and Spelter), and lead for the bullets. They're made in the Cartridge Factory or Reloading Bench.
- One of the great challenges of this mod is that while your industries will require a broad range of resources to operate, most embarks will not have all of them. While in DF this is a minor problem, in the Underhive this a major one. As a result you will need to trade for what you don't have - whether that be flux, coal, halite, uranite or prometheum.
- One thing that can work well is to put a good premium on Junk Piles and process them for Finished Goods that you can then trade for more Junk Piles. If you have access to gems - and most embarks will - you can encrust the trade goods to increase their value even further. (In the setting for the game, there are numerous settlements that get by entirely on this process.)