|This article is about the current version of DF.|
|This article contains massive spoilers. If you do not wish to have your game experience spoiled, do not scroll down!|
- "Hidden fun stuff" and "HFS" redirects here. For other hidden content in the game, see easter eggs.
The Underworld is the absolute bottom of the world, reached by digging under the magma sea and breaching a hollow raw adamantine vein. A massive open cavern of slade, it is decorated with giant, bottomless eerie glowing pits (which will instantly kill anything that falls into them, unless floors are constructed over them) and serves as home to demons, who will immediately rush to the nearest exit they can find, typically leading to overwhelming amounts of fun. Breaching the Underworld serves as the end-game of dwarf fortress mode for those daring enough to do so.
The Underworld expands out in all directions without bound with a height varying between 1 and 4 z-levels. Its rough floor slopes up and down, making it possible to walk around and explore should you get an adventurer down there. If you dig down through a hollow adamantine pillar, but had previously blocked off the particular hallway with a drawbridge and raise it, you can discover the location of all adamantine on the map with no negatives.
Demons spawn on the edges of the Underworld much like animals do on the surface; demons thus spawned will be content to meander without going out of their way to extinguish all life they can reach. It is yet unclear whether the number of demons is finite; in information exported from the legends screen, the population of demonic species is listed as "unnumbered," a descriptor usually reserved for ants, worms, and other omnipresent vermin. Clusters of webs can be found scattered across the Underworld's surface, marking the presence of demons able to spew webs as a form of combat.
Upon first discovery, the place is referred to as an eerie cavern. Nearly all other references in the game, including dialogues and descriptions, call it Underworld or underworld.
Hell is a popular alternative name among DF players due to its hellish overtones, but it is rarely referred to as such in-game. Hell is included in the game's languages, and generated names for people, sites, regions, etc., can contain the word hell. When the Underworld and its contents are spoken of in the context of spoilers, players frequently use the term "Hidden Fun Stuff" (HFS) or the "circus" (with demons nicknamed "clowns").
 Reaching the Underworld
Upon digging sufficiently deep (usually z-level ~160, but it can vary wildly) you will find huge magma lakes. These are surrounded by semi-molten rock which cannot be cleared by digging, but seems otherwise stable. Eventually, you will reach a layer which contains nothing but molten rock and little to no possibilities to pass. You can reach the critical layer by digging through solid rock which gets rarer the deeper you dig. In fortress mode, there are two ways through the impassible layer:
Digging through an adamantine vein: Raw adamantine veins are shaped like vertical tubes and breach through any layer of semi-molten rock, right down into the Underworld. The lower layers of the vein are often hollow and act as a tube, leading straight to your doom. Breaching into the hollow center of a vein has the same effect as breaching into the Underworld, so beware. You could easily dig around the hollow core provided you knew where it was, but every vein's hollow center is located at a different height - the risk is all part of the fun. Adamantine veins always seem to end in mid-air, so once you breach the final layer, you will face a horde of demons which hovers directly below your feet.
Channeling through semi molten rock:v0.42.06 It is possible to channel into semi-molten rock (and, to a lesser extent, slade) from above, as long as the tile below is not yet discovered. In older versions, you had to remove the magma-flow and ramps in a complicated procedure, that killed one dwarf per level, but now it is possible to channel directly into the underworld without losing a dwarf (though the miner tapping it will likely get killed by demons or drop into an eerie glowing pit). The difference is that in older versions the miner was placed onto the magma flow, but now he is placed under the magma flow, and can channel on.
- Start one or more levels above the lowest rock layer above the magma flow. (this is important, as the miner must fall below the magma flow)
- designate channels (d-h) from here down to the bottom of the map.
- The miner will first generate a downward ramp into the rock. Now build a hatch above this ramp.
- The miner walks down this ramp, and channels into the semi-molten rock, as the game only sees the granite upward slope.
- Now, the miner is trapped below a magma flow (floor) and surrounded by semi molten rock. He will proceed to channel down until he reaches the underworld, leaving magma flow tiles above him, as well as channel one level into slade. (if he survives long enough)
- You now have a chute - blocked by magma flow floors - into the underworld. By constructing up/down stairways, you can build a stairway into the underworld (the magma flow is removed in that process).
- If the site has no adamantine (otherwise you probably wouldn't do that), no demons will be generated (except the "wildlife"-demons), and you might even be able to save the miner, if you build the stairway, before he starves to death.
- As both magma-free pillars and eerie glowing pits are placed in the corners of embark tiles, the miner will likely fall into an eerie glowing pit - use zones ( ) to find solid slade floor and prevent this from happening.
You will receive an announcement upon piercing the Underworld. One step later, you will get a second announcement: "Horrifying screams come from the darkness below!" At this point, a massive number of demons will be spawned - though the number is not fixed, the demons will likely fill many pages on the Units screen. You'd do well to prepare for the worst.
 Adventure mode
In adventure mode, one may find huge slade underworld spires built as gateways to the Underworld. The lowermost levels of these structures indeed lead directly into the Underworld, with several demons waiting below.
 Invading the Underworld
Assuming you survive the initial onslaught, you may then proceed to explore the newly discovered land. The most impressive example of this feat is recorded by Sethatos in Archcrystal. Dwarfs of the highest skill are recommended.
|"Underworld" in other Languages
|General|| World Generation (Basic / Advanced / Rejections) - Map legend|
Climate - Surroundings - Civilization - Holdings - Calendar - World activities
|Biomes|| Chasm - Desert - Forest - Glacier - Grassland - Lake - Mountain |
Murky pool - Ocean - River - Savanna - Shrubland - Tundra - Wetland
|Underground||Cavern - Magma sea - Underworld|
|Features|| Aquifer - Brook - Deep pit - Island - Magma pool |
Passage - Road - Tunnel - Volcano - Waterfall
|Sites|| Camp - Cave - Dark fortress - Dark pit - Forest retreat - Fortress - Hamlet - Hillock |
Labyrinth - Lair - Mountain halls - Ruins - Shrine - Tomb - Tower - Town - Vault
|Structures|| Catacombs - Dungeon - Keep - Library - Market - Mead hall |
Sewer - Tavern - Temple - Tomb - Underworld spire