Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[DruchiiConversion]

Having a slightly weird issue with my current fort.

On a 2x2 embark, with the first fort I've played in a newly genned region. Things were looking fine - my economy built to the point that I was ready to start digging down in pursuit of magma, hit the first cavern at z-level -24, which seems pretty standard for my experience so far. I walled out that cavern, and carried on digging.

Then things started getting odd.

At z-level -36 I got the announcement "You have discovered an eerie cavern. The air above the dark stone floor..." etc - the usual announcement message for the beginnings of things Fun in nature. Then next frame... nothing. No followup announcement. So I took stock of what I had beneath me...

I found a large square section which was just solid rock in the SW side of the next z-level. It was perfectly square - no deviations from straight lines on either of the two faces exposed to me. In the entirety of the rest of the z-level was open space - nothing at all holding it up except - presumably - the edges of the map. The only other feature on this z-level was a small section in the NE side of the map made of slade.

With so much empty space, I could see other things. On the next 4 z-levels down, there's a similar square of solid rock in the same place as before, the only changes being the slade section getting larger, and by the fifth (and final) z-level where the solid rock cube exists, the eastern side of the map is just a full top-to-bottom floor of pure slade.

On the next z-level down, there's no more rock cube! The left side of the map loses its big obvious cube, and instead is replaced with... empty space. Most of this empty space - and the empty space surrounding the slade on the other side - is red (maybe suggesting magma at the bottom?) but there's a big chunk in the middle which is just the usual grey dots. Going down more z-levels this too becomes slade, in a vast block of gently sloped cavern floor leading to an abrupt stop a few z-levels down, and just empty space beyond it.

The only real change that's visible to me at the moment is z-level 53, where I start to see the map edge tiles - or at least some of them - on the western edge of the map start to contain magma, to a depth of 1/7. Beneath them are more magma 1/7 tiles, and I suspect that this is actually a waterfall where magma is flowing onto my map at this z-level, then finding nothing but empty space to support it - so it's falling down into parts unknown.

Is this standard?? I've never found HFS before - just a regular magma sea containing adamantium which I left right the hell alone - or am I looking at an interesting worldgen bug? Or have I found the first ever fortress of the demons, from whence they came, muhahaha-sorry, I'll stop...

(can provide screenshots if needed, but I'm expecting someone to smack me and say "this is common, happens all the time, here's the wiki article". )

[proxn_punkd]

I think a demon fortress is noted as "a curious underground structure". I'm pretty sure it's supposed to be full of zombies.

As a quick experiment, get some mechanisms, set up a lever, and try to connect it to a |S|pear trap. If there is a fortress, a shiny sword will appear on the list of things you can link.

[DruchiiConversion]

No shiny blue sword on my list of link-uppables.

Are demon fortresses usually surrounded by that much empty space? We're talking thirty, fourty z-levels here of just... nothing but slate exterior. No rock surrounding it at all, beyond that five z-level cube right at the top. Getting to the bottom (presumably where the entrance is?) would be mammoth task enough, let alone beating on any zombies inside.

[SpiralDimentia]

Screenshots. I must see this.

[NecroRebel]

This sort of thing happens when you've got extreme z-level changes. The cavern layers, including the bottom layer and the magma sea layer, are shifted up or down depending on the topography of the map so as to maintain a roughly-uniform thickness. This shifting happens every local tile on the embark map, which corresponds to a 48x48-tile square on the playable fortress map. If there's too large a z-level change over a space, this layer shift can put the top of hell in one local tile at or above the bottom of the magma sea in an adjacent local tile (happening in perfectly straight lines along the edges of those local tiles), meaning you can "breach" hell simply by discovering the sea or, in even worse cases, even the lower cavern layers.

I'm not sure about what might've prevented the second hell-discovery announcement from occurring, but there's 2 possibilities I see. First, you might not actually have any adamantine; this means that there's no adamantine tube that the "horrible screams" can come from, so they don't happen. That's unlikely-to-impossible on a 3x3 map, however, as normally there's one tube per 2x2 area. Second, it might be the case that since you haven't actually discovered the bottom of the adamantine tube that the screams come from, they haven't occurred. In that case, they'll happen as soon as you do find them.

[DruchiiConversion]

Alright. Screenshots ahoy!



This was taken basically straight away upon seeing this new level, so may be slightly inconsistent with the others, which have all been taken just now. I dug in through the middle of the red in the middle, through a layer of microcline - I was just tunnelling straight down aiming for magma. Wasn't really expecting any trouble - I hadn't even hit the second cavern yet! Pictured is the square face of rock to the bottom-left, and the tiny first sighting of slate in the top right.



This is the bottom layer of that cube - the z-level now is -41, compared to -37 for the first level of the cube. You can see the large amount of slade on the right side of the map, which makes up nearly half of my entire embark.It also extends round to the top-left, too, and out of sight.



One z-level down from the cube, we hit empty space - and there we can see the other enormous slade construction on the left side of the map. The little bit of smoothed out wall and stairs you see there is my beginnings at construction into this empty hellhole. Originally the plan was to get to the pre-existing rock quickly with stairs, surround the stairs with walls, then dig down into the rock in safety - obviously back then I didn't know slade was unminable.



This is a bit further down, and is mostly a screenshot to show the magma on the edge of the map. Though it does show just how much of this embark is entirely slade at this z-level.



This is z-level -90, and is about as far down as I can realistically be confident that these enormous towers of slade extend for. Below that, Armok only knows.

[SpiralDimentia]

oh my god that's awesome.

[DruchiiConversion]

This sort of thing happens when you've got extreme z-level changes. The cavern layers, including the bottom layer and the magma sea layer, are shifted up or down depending on the topography of the map so as to maintain a roughly-uniform thickness. This shifting happens every local tile on the embark map, which corresponds to a 48x48-tile square on the playable fortress map. If there's too large a z-level change over a space, this layer shift can put the top of hell in one local tile at or above the bottom of the magma sea in an adjacent local tile (happening in perfectly straight lines along the edges of those local tiles), meaning you can "breach" hell simply by discovering the sea or, in even worse cases, even the lower cavern layers.

I'm not sure about what might've prevented the second hell-discovery announcement from occurring, but there's 2 possibilities I see. First, you might not actually have any adamantine; this means that there's no adamantine tube that the "horrible screams" can come from, so they don't happen. That's unlikely-to-impossible on a 3x3 map, however, as normally there's one tube per 2x2 area. Second, it might be the case that since you haven't actually discovered the bottom of the adamantine tube that the screams come from, they haven't occurred. In that case, they'll happen as soon as you do find them.

I'm on a 2x2 embark, so I reckon I've a 3/4 chance of simply not having a tube at all, at a guess? That would explain why I didn't have to deal with immediate demons.

That said - I've not even breached the second cavern yet! Can it really be shifted up that far? As you can see, there *is* no second cavern - just empty space, all the way down to z-90 and probably beyond, with very little rock in it that's not slade. Similarly, I've not discovered a sea of magma - at least, one hasn't been announced - I just have a vast chasm with two enormous slade blobs in them, with magma waterfalls for walls, and no life down there at all that I've seen. Similarly, it's not a cavern - no plant life, no wildlife, just slade slopes and empty space.

[NecroRebel]

I'm on a 2x2 embark, so I reckon I've a 3/4 chance of simply not having a tube at all, at a guess? That would explain why I didn't have to deal with immediate demons.

Around a 68% chance, actually (1-.75^4), assuming I'm not failing my math (which is entirely possible; for whatever reason I'm having trouble conceptualizing it right now). The 2x2 blocks that each have a tube in them are determined independently from your embark, so you've just happened to shoot into a place where there's no tube. It also means that you'll never get a demon swarm on this embark.

That said - I've not even breached the second cavern yet! Can it really be shifted up that far? As you can see, there *is* no second cavern - just empty space, all the way down to z-90 and probably beyond, with very little rock in it that's not slade. Similarly, I've not discovered a sea of magma - at least, one hasn't been announced - I just have a vast chasm with two enormous slade blobs in them, with magma waterfalls for walls, and no life down there at all that I've seen. Similarly, it's not a cavern - no plant life, no wildlife, just slade slopes and empty space.

It is possible in cases of extreme elevation shift. Under default worldgen you need a ~15 z-level shift over a single local tile for the magma sea to meet hell, with another ~10 for each additional cavern layer, but there is variance involved. Still, if you've got a near-vertical cliff (or volcano, which amounts to the same thing) of 40 z-levels on your map or just off it, that would explain it.

The magmafalls that you're seeing are usually due to the magma sea draining into hell, while the barren slade slopes and empty spaces with red-crosshatched eerie glowing pits at the bottom are typical of hell.

[SpiralDimentia]

Similarly, it's not a cavern - no plant life, no wildlife, just slade slopes and empty space.

The Gods wants you to build a base here. Out of something other than slade, obviously, but this is where your Fortress must be.

[DruchiiConversion]

Okay, fantastic, thanks for the help.

What's standard operating procedure for this sort of situation, then? Am I likely to find magma at the bottom or this, or just more slade floor in the distant depths? Even if I do, building a pumpstack to pull my magma out of hell itself is... an unpleasant plan, which sounds like a *lot* of scaffolding work.

For that matter, will the magmafalls eventually fill up to the height at which they're entering the map? I figure I've a *long* wait if that's going to happen, but...

[NecroRebel]

The eerie glowing pits act as infinite sinks; anything and everything that falls into them is lost forever. So no, hell will never completely fill. And no, there's no floor in the distant depths; there's a distinct map bottom that you can't go past will be composed solely of slade and eerie glowing pit. Since you've likely got no demon swarm to worry about, hell is actually a fairly safe place. Still, dwarfyness demands hell-colonization!

[DruchiiConversion]

I think I'll leave the hell-colonization to someone to whom it would mean more than I... I don't even recognise this place as being particularly hellish, after all. To me, it's just really, really inconvenient, and has effectively killed my fortress just by being boring! Damnit, I wanted to flood my fortress with magma!

Thanks for all the info.

[Reelyanoob]

Try sealing off some of the magma-falls, I'd put walls on each side first (with floor walkways outside the magma area) & then bridges to seal the bottom, then you'd have your own reservoir. That would make for a fun mega-project, and you'd get 100% of the magma for yourself.