v0.31:Megaprojects

Instead of deliberately inhibiting yourself, create a wonder of the dwarven world that would make the Mountainhomes proud. Be sure to upload it to the Dwarf Fortress Map Archive when it's finished. More projects can be found where stupid dwarves try crazy tricks. Incredible feats of construction are usually very fun so you'll see many different (and probably similar) constructions across the Wiki. Use whatever ideas you think are ingenious.

Aqueducts

For some reason, a noble was harmlessly pulling a lever when suddenly, magma flooded the river and exploded the booze! The king requires your band of seven to build a great aqueduct to bring water to the capital. Start with supports, and build up your aqueduct until it is 10 z-levels high!

Bonus: Start over a human town, build a wall around it, pump water through the aqueduct and into it!
Bonus: Mod the game so you can start on the dwarven capital and actually bring about the story.
Bonus: Once you have completed your aqueduct, embark in a slightly different location and build the next section. repeat until you've built it all the way to the capital!

Variation: On a map containing a river, completely enclose it with glass walls, and floors. Use overhead pipe sections to move the water to places more ~~convenient~~ Fun.

Blood for Armok, God of Blood

Worship Armok by spilling copious amounts of blood. Paint every single outside tile red with blood. No blood rains allowed, of course. Rain will be your worst enemy.

Bonus : No water flooding with blood. All the blood must be genuinely spilled, so that Armok does not call you a cheap imitator.
Bonus : Paint your entire fortress red with blood, as well.
MegaBonus : Paint the caverns red with blood, along with every single inside tile. Be sure as well to make every single water source red, except the one you use for your wells.
UltraDwarfBonus : Paint HFS red as well ! BLOOD FOR THE BLOOD GOD !

Biodome

All material, seeds, food, tools, and dwarves must be in the fortress within one year. Then, seal up the entrance. Any new immigrants... well, they might be in trouble. Survive for as long as possible!

No chasms/underground rivers/magma vents allowed.

Casting

Who needs to construct giant statues?! We need ours made from natural walls, however, we want it above ground level as well. For casting your goal is to create some giant structure out of natural obsidian walls through the use of an extremely elaborate scaffold of lava and water pools and screw pumps. When you are finished, just deconstruct the scaffolding and smooth/engrave the statue as you go. Just imagine the bridge over that chasm, now complete with two giant dwarf statues on either side to strike fear into all who enter and to show them the power of your fortress.

Bonus: Make the statues spit lava.

Castle

Build a castle, greater than anything built by human, elf or dwarf. This is highly time consuming if you want it to be a good castle. There must be floor indoors, and no underground constructions except for mining operations and cellars. For an even greater challenge, build a gigantic tower in the middle, where the nobles stay.

Ceremonial Sacrifices

Build an amazingly complex or spectacular killing device. A shaft that extends across the entire Z-plane is a good start. A constantly shifting maze of atomsmasher drawbridges is another. For the minimalist, a very confined space where you will drop a dwarf wrestler along with the gobbos once in a while. Perhaps a waterslide that carries your prisoner all the way down into a chasm? Just cut their heart out? Whatever your idea, build it and dedicate your fort to the construction, maintenance and improvement of your device.

Do not kill any of your invaders. Capture them using cage traps, and them set them off in your device. Keep a record of the number of victims you drop into it.

BONUS: Create a statue garden to memorialize your victims, with one statue per victim. Structure your fortress such that sacrificial victims have to pass through the garden on the way to their demise.

Computing

Can your dwarves build the Antikythera mechanism? Can you program the fortress to play tic-tac-toe? More details at computing.

Colosseum

Build a pit, around it on steps lots of Thrones, make the whole thing a meeting area, train Gladiators, capture goblins, leave them their weapons and let them fight against your gladiators. If they win, let them go.

Crematory Fortress

Requires a magma pipe and bauxite.

Build a temple structure above a magma pipe and engrave every available surface. The temple should be as opulent as possible. In the temple, build a retracting bridge over a hole in the floor, and designate a coffin stockpile on it. Whenever a dwarf dies, build a bauxite or other magma-proof coffin for him, place it on the bridge, and retract it, committing his body to the fiery blood of the mountain.

Note: Since coffins are unassigned and emptied when deconstructed and cannot be constructed on top of a bridge, this will not actually work. An alternative would be to place the coffins in individual chambers which can then be flooded with magma afterwards.

You could expose the magma pipe, build a one-tile wide floor span across it, and then above that build a support that holds up your temple floor on the z-level above. The temple floor would be separated from the walls of the temple and would be connected for walking access diagonally. The support holds it up. You would have to construct the coffins in the temple, then when someone gets buried you pull the lever attached to the support. You then rebuild the narrow span below, the temple floor, and the support, then link the lever to the new support.

You can do this without scaffolding if you build the temple floor access straight in, and then the span below and the support, then once the support is in place you destroy the straight temple access leaving only a diagonal temple access.

Another method would be simply to make a hole in your temple that goes straight down to the magma, of at least 3X3 squares, then build a floor of 2 squares long and 1 wide from the upper middle edge of the hole so that the second square is only connected to the temple by the first, then build your coffin on the second square and once your dwarf is inside deconstruct the first square leaving nothing holding the square with your coffin up and it will fall into the magma. On a side note it is best to start from the upper edge of the hole so the dwarf doing the deconstructing is a lot less likely to fall into the magma.

Retracting bridges work well to provide access to build the support and floor, and can then be retracted before dropping the coffin. Use a single lever to retract the bridge, then begin filling a chamber with water to trigger a pressure plate to destroy the support, dropping the coffin, and also draining the water to encase the coffin in obsidian.

City

Live like a human!

Build all of your buildings above ground. to make this easier, mod in a plentiful building material similar to bricks, however you want it. Make sure that your city is unplanned for that medieval look; build when you need to as close as you can to where it needs to be. As each migration wave comes you're going to need more and more buildings. Protip; you're going to need a caste of dedicated builders.

Extra points; Emulate your favourite city.
Combo bonus; Build your city around some other megaproject; a pyramid or giant colloseum.
ULTRADWARF; Start in a mountainous area and hollow out the above ground city from the projecting mountains, including all four sides, thus leveling the mountain range to leave a series of *surprisingly natural* looking streets.
Build each building (or section of one) out of the same materials or...
- Bonus: Create pixel art from the colors of the stones!
- Bonus: Try to build all freestanding structures
Geek Reference Bonus: Build the city on the side of a mountain, using only marble, and make it look like Minas Tirith.

Doomsday Clock

Build a water or mechanical clock whose final state triggers the support which holds your fortress up or a megabeast out. See how much wealth you can achieve before the clock runs out.

Bonus: Create something that resets itself, as well as purging the map, so that you can reuse the same fortress over and over.
Super-Bonus: Create something that involves pressure plates and a small kitten, when the pressure plates are hit in the right order, your map ends. Toss the kitten in and hope for the best. Alternatively, make the sequence quite unlikely, but add 2 kittens; breeding introduces a probability of doomsday that is a function of time (depending on the mechanisms involved)
Super-Bonus: Create the super-bonus above, but place the kitten on the lowest Z-level and never return to either look at it or see how many of the conditions for the doomsday device have been met. This way, the kitty mimicks Schrodinger's cat: we cannot observe the state of the kitty, but we can infer it from the state of the world (spin-pairs effectively).

Dungeons of Doom

Beneath your fortress, carve out an immense dungeon starting from the surface. Each dungeon floor must be filled with rectangular rooms connected by twisting one-tile passages, with an occasional wider hallway, and each floor must lead to the next by a single-tile staircase (no up/down stairs). A few floors into the dungeon, build a small fortress and designate a few quarries away from the dungeon itself. The dungeon should not be exposed to the caverns, but the caverns should be exposed to the surface to free the fun creatures. The dungeon must go down until it reaches HFS. Dump an artifact amulet inside HFS. Build puzzles and thematic branches of the dungeon as you see fit.

Bonus: Fill the dungeon with gnomes, goblins, kobolds, and horrible monsters of all kinds.
Mega Bonus: Litter the floors of the dungeon with artifact items (especially weapons).
Cosmic Bonus: Lead the dungeon into an upright spoiler and build a Labyrinth inside HFS.
Nerd Bonus: Build the last few levels above your fortress, and fill one with lava, one with water, one entirely empty, etc, to mimic the last few levels of NetHack. The uppermost one should have three temples, and if possible megabeasts that cannot escape but which an adventurer could reach...

Dwarf like an Egyptian

Build a pyramid of epic proportion.

Build a legendary dwarven pyramid, with a corridor running to a central tomb for your favourite noble. Then construct lots of different traps in it to avoid grave robbery. Perhaps build it entirely out of glass? Or try to make the top twist in a bit of a swirl. Alternatively, make your entire fortress inside a pyramid, which stretches below the ground.

Build rows of Obelisks

Build a double row of Obelisks before the Pyramid, and engrave the sides. Build ramps on the tops.

Build the whole thing upside down.
- And then another one on the upside-down one.

BONUS: Make a Sphinx out of solid gold. Solid! Nobody lives or goes inside of it. Entomb the builders in an unfortunate accident - preferably inside the sphinx - so that they can never build one for anybody else.

When the time has come, or when your fortress is about to be destroyed by a siege or something, perform the ceremony to translate the mortal form of the noble to the underworld. Give him a ritual death, and make sure you kill his servants as well. Pile wealth into the tomb. If the tomb is built for your king make every dwarf die but one, who inters everyone into their resting place. His final act will be to pull a lever that seals the tomb as well as kills him. Then enjoy going back and reclaiming your fortress to observe your efforts.

BONUS: Dwarf like a Sumerian and make the Pyramid a Ziggurat.

Graveyard Master

Every dwarf deserves a decent resting place:

Build a tomb for every dwarf that dies, the more dwarves you manage to bury the better.
Tombs must be rooms with exactly 5x5 of size and 1 of height, with only one entrance tile that must be closed by a door.
Tombs must have all its surfaces engraved.
Tomb must contain at least 4 statues.
Once complete, the door must be replaced with a wall and the tomb must not be ever entered again.

How high can you go?

Construction, construction, construction! Just how big a tower can you build? Out of glass maybe, clear glass? Steel? Pump water to the top? Make your tower a pinnacle of achievement and stun humans, elves and goblins alike - for they know nothing of construction and engineering like dwarves do!

Land battleship

Turn your mountain into a huge battle-station, complete with crew quarters, decks, command centre, cantina, and a large collection of deadly weapons : Batteries of marksdwarves, ballista cannons, catapults, boarding bridges and teams, but also lava projector or remote explosive devices (ie cave-ins in a part of the map triggered by a lever). Make sure it ends up looking like a real battleship, with nothing but plains surrounding it (you could build it on an actual plain, or destroy a mountain, choice is yours). The battleship has to be autonomous, and dwarves shouldn't wander outside it.

Bonus: The weaponry covers every tile of the map (i.e., everything that enters the map can be shot)
Bonus: Build several other ships, maybe dedicated to a specific product (food, ammo etc.)
- Bonus: Find a way to let them fight each other in a naval battle
Bonus: Each crew member has a civil and military formation, and when the enemy arrives, stop every economic activity. All hands to quarters !
Bonus: Rebuild Noahs Ark: Completely out of wood, with every animal twice, as well as one dwarven family with three sons on board. Flood everything around it AND LET EVERYTHING NOT ON THE ARK DIE!!! MUHAHAHA!!! FEAR THE WRATH OF ARMOK!!!!!
Mega Bonus: Use lava instead of water (Although you shouldn't use wood, as it will burn, unless that's your intent

Labyrinth

Build or dig out an elaborate labyrinth. It should be filled with traps, periodically flooded with water and magma, and decorated to your liking.

Bonus: Build a prison and/or execution chamber somewhere inside the labyrinth.
Bigger Bonus: Build all the labyrinth walls out of statues and make the entire thing a statue garden.
Mega Bonus: Make it three-dimensional.

(A labyrinth is a unicursal maze: labyrinths offer no choices of path as they curve in and back on themselves to the endpoint. Mazes usually have choices of paths and therefore usually dead ends. Given how pathing will usually let sapient beings in DF avoid dead ends, a labyrinth is preferable to a traditional maze with dead ends.)

Daedalus has many maze algorithms and tools, including for unicursal mazes (GPL, free). A traditional maze generator may be helpful if you somehow open the dead ends (such as with drawbridges) to attract traffic.

Moria

Build a huge hall - at least 3 z-levels high. Leave few pillars symmetrically placed in the hall (don't build them, carve them out). Smooth and possibly engrave everything (not only the lowest z-level!). Then build thin bridge (not the bridge building, just a thin piece of rock to walk on) above magma or above a chasm- support it with bauxite supports connected to a lever (bauxite mechanisms needed in support). Destroy stone holding it at the both ends and replace it with floor hatches (so when you pull the lever it all goes down). After that build a bridge above the chasm. When it's all done seal your dwarves deep inside in safe place and get invaded by goblins. At the same time dig out HFS. Lead the HFS across the both bridges and then collapse the second one when one of the champions clashes with it (it doesn't matter that the champion has killed the HFS with one hit).

bonus - cast the walls of the hall out of obsidian using water and magma

Mountain audit/core sample

Start in a mountainous area and strip mine everything down, down, down to ground level. Stockpile everything, and calculate the mountain's composition. For kicks, try not excavating one tile on each z-level. You'll be left with one enormous core sample.

Project Mayhem

You do not talk about project Mayhem
Build a series of towers, at least 10 z-levels high, of different size and shape. They must be supported by a series of supports linked to a lever.
Store all your riches in the towers : crafts, precious metal bars, gems, artifacts, everything. You may also want to house your nobles on top of the towers.
Pull the lever and watch the collapse of financial history.

Bonus : make the towers' walls out of glass!

Bonus : Make soap! And remember, elf fat is ideal...

Extra Bonus: Make one large tower, and make it collapse onto a smaller tower, filled with all your artifacts/engravings. (Essentially, you only get the extra bonus if you've read the book)

Santa Claus

Get ten thousand toys built and offered to caravans yearly. Optionally, build ten thousand toys, fetch them in adventure mode and deliver them to every single city of the world.

BONUS: Make the toys out of lead.

MEGABONUS: Modding Elves to be pets, embark with 100 of them and force them to make the toys for you.

Skull collector

What proves the might of a civilization better than a hall full of skulls?

Try to collect as many skulls as you can during your fortress life, and put them in a special skulls-only storage. The more skulls the better.

BONUS: Cover all the skulls in blood, and make the stockpile also a throne room. Blood for the Blood God, Skulls for the Skull Throne!

SUPERBONUS: Also fill the throne room with kittens.

Space Ship

Create a giant space ship fit for space travel. It should be able to hold about 100 dwarves for at least 2 years.

BONUS: Use exploding booze as ignitable fuel.
BONUS: Make a removable ramp for boarding.
BONUS: Make the water for the 2 years be on the ship using removable pumps.
BONUS+: Make it totally self sufficient. (Make an internal system which pumps the water supply through a room every few years to muddy the floor. Plant seeds in the mud that's now on the floor. Manage your consumption to maintain self sufficiency.)
Modding BONUS: Mod the game so that merchants can fly their new wagonships into your docking bays. (If possible)
BONUS+: Make it all out of steel and aluminum.
FUN: Let it be held by a single support, ignite the booze, remove the support an let it "fly".
EVEN BETTER: Drop it down a chasm.
More FUN: Set up a mining operation on the surface and dig into the HFS. Watch the alien creatures take over your ship and hunt down your dwarves. Form a squad of heroes to overload the booze reactor to prevent the aliens from reaching earth. (See Dead Space and/or the Alien series)

This Was A Triumph

Build Aperture Laboratories, with marble test chambers supported by struts and columns of granite. Lab should have (Connected through paths)- 1) Multiple test chambers, with observation booths and connecting staircases/elevators. 2) An end goal, with an incinerator. 3) Background systems, with catwalks and large areas of waste management. 4) An AI Control Chamber. 5) A cake chamber (with a cake, obviously)

BONUS*- Make an entire model of the original Portal chambers
BONUS*- Make a sealed off area, the original testing area in Portal 2 (Include a statue of a Noble named Cave Johnson)
BONUS*- An extended map, including the Subject Suspended-Animation life support system
BONUS*- Make a field on top with access, a single small shed
BONUS+*- Build a 20:1 model of the Companion Cube

-**RIDICULOUS-YOU-ARE-GOD-BONUS**- Build an extremely elaborate mechanism which, using a number of levers in the AI room, will trigger the appearance of floodgate walls and other furniture that will compose an Aperature Modular Test Chamber. Make it so that you can build several room arrangements without using a single dwarf (except to pull the lever maybe)

Swiss Precision

Build a working clock. The clock should accurately track DF days, months, and years.

Bonus Points:

If the clock has a mechanical effect in the fortress proper to announce new days
If the clock creates seasonally appropriate effects at the change of months and/or seasons.
If the clock is used to aid in the operation of the fortress in addition to its role as a clock (automatically controls farmland irrigation at particular times, automatically opens the ~~blast doors~~ ~~floodgates~~ ~~Magma Channels~~ Gate in time for those ~~evil~~ friendly merchants, etc...).
If the clock governs the schedule of a working rail station (which is always on time). (Definitions of 'working' and 'rail station' are subject to player imagination).
If the clock takes measures to protect itself. "I can't let you do that, Urist."

But don't worry about the bonus points, a precision time device should be hard enough.

Temple

Designing a temple to Armok. Aesthetics count - the god will be very angry if there is no flowing blood in there, no sacrificial pit, no engravings, and no domed ceilings carved with frescoes.

BONUS : Make your arena inside the temple and make regular sacrifices for the God of Blood. Blood must NEVER be cleaned, of course.
MEGABONUS : Add magma. Add iron spikes everywhere. Impale enemies on these spikes and keep them here.
MEGADWARFBONUS : Cast it all out of obsidian, add all of the former elements. Make it a replica of a Gothic cathedral : http://en.wikipedia.org/wiki/Gothic_architecture

The cube

Play a fort as usual, but emphasize catching goblins in cages to support and fill this construction: Construct a series of rooms in a symmetrical fashion, all connected to each other with appropriate doors. Of course, enough rooms to make a maze-like structure, and if you feel like it, an exit that is hard to reach. Fill a bunch of the rooms with traps and pressureplates. Then fill one room with 4-6 goblins (preferably in cages, opened by an outside lever), release them and watch them randomly walk around the rooms dying to traps and whatnots.

Bonus: Do multiple story maze (3d-maze)
Bonus: Use pressureplates to open/close the exit randomly; otherwise, all the goblins will just follow the shortest route to the exit.
Bonus: Use multiple doors connected to multiple pressure plates in order to access certain rooms, so the goblins have to go through the maze in the correct order.
Bonus: Figure out a way to have competing teams wandering through the maze at the same time. Can you say "elimination round?"

The great brewery

Disaster has struck the kingdom. A strangely glowing ‼peasant‼ visited the greatest brewery of the empire, and as a result the whole thing exploded. No time for weeping — create its successor, a fort dedicated to alcohol production, and get the alcohol supplies flowing! Try to make the widest variety possible, and give or trade it to the dwarven caravan each year.

BONUS: Create a working sprinkler system to douse any fires that might occur.

The Great Wall of Urist

Build a dwarven great wall of china that splits the map in half. Must be at least 10 tiles thick and reach the highest z-level.

BONUS: Make it block the ~~mongols~~ goblins out of your half of the map.
BONUS: Make it out of obsidian.
- BONUS+: Embark on a map without obsidian.
BONUS: Find a way to make it touch the boundaries.
BONUS: Build one gate
BONUS: Arm it with ballistas.
- MEGABONUS: Once you have split your embark in half, abandon the fortress and embark adjacent to it, and continue the wall until it splits the continent in half.

Someone should make a bonus for this but I'd like to point out that the actual wall was made from (compressed) dirt with on outer layer of stone and that the bodies a those who died from exhasution while building it were put into it.

- BONUS+: Encase all workers who died during building in caskets built into the wall. Possibly with traps to protect them from grave robbers
I'd like to point out that it is just a myth that the bodies were put into the wall. In reality, they were buried nearby.

The Monolith

As the inevitability of a fortress-wide mental breakdown looms over every single fortress why not have something that alludes to that precipice of insanity. Like the book and feature film, 2001: A Space Odyssey you must have a Monolith. This has to be made from obsidian and have a completely smooth surface (You cannot build it from blocks) You can have it be any size as long as it is outside, at least 2 tiles thick to ensure there are no pillar tiles, and has about the same ratio of width to height as it does in the movie (1:4:9) to make it as close to the real thing as possible. It would be preferable to make it large so that it seems to be dominating the landscape and your dwarves' psyche. The bigger the better.

If the rock obsidian strata isn't deep enough in parts to make a monolith feasible consider casting a monolith with a large rectangular block in the exact same dimensional criteria as above.

Statue of greatness

Build a giant statue, spanning 10-20 z-levels and make it in the shape of say, a dwarf you like or an animal you like.

Bonus: make it in the shape of a teapot that has a working boiling system and a spout that water can come out of.
Bonus+: Steam instead of water coming out of the spout.
Bonus++: Magma mist instead of steam coming out of the spout.

Underwater fortress

Encase your entire fortress in water! Your fortress should be watersealed: surrounded by water against all walls and the top of the fortress.

Bonus: Build all water-touching walls/roof in clear glass!
Bonus: Use magma instead of water (warning: will almost certainly lead to fun)!
Bonus: Build it in the ocean or a non-freezing lake
- Bonus: Build it in the magma sea
Bonus: Build large glass domes that encase the fortress. A dome 20 tiles wide should be 10 z-levels tall (creating a hemi-sphere). Which may be hard to cover in water.
Bonus: Have a mechanism for dropping your enemies into the water to drown! Or fill the water with carp.
- Superbonus: Don't use pansy walls, use pumps to keep the water out!
Mod: Make your dwarves amphibious and include airlocks between the wet fortress and the dry.
Remake: Make Rapture city from Bioshock
- Remake Bonus: Mod in plasmids to give dwarves superpowers, but will eventually drive them mad!
  - Remake MegaBonus: Big Daddies for military, anyone?
    - Remake MegaDwarfBonus: Edit the save raws and name the mayor "Andrew Ryan".

Flying fortress

Turn cave-ins off in the init, the build a flying fortress. Perhaps some flying islands only connected with bridges, maybe combined with an orbital defense network.

Bonus: Turn cave-ins back on.
History Bonus: Try and make them look like B-17 Flying Fortress bombers from WWII.

Wealth

The kingdom's coffers need lining, so hop to! Found a fort and start accumulating wealth as fast as possible. Attain as high a fortress value as possible, and make most of your wealth into coins for the vault. Try to beat your record for one year, two years, or five years.

We Are Dorf

Embark site biome parameters: Mountain. Fortress shape: Cubicle (assume 7 tiles high), cut from natural rock and separated from the remaining stone so it is held by a single support. Migrant dwarves must report to assimilation chamber where a collapsing dust trap will launch them into large serrated disk traps to remove unnecessary appendages, or have their offending limbs removed some other way. Dorf drones must be cataloged and arranged in squads of varying number. The naming structure is as follows: First of Ten, Second of Ten, and so on. Clothing is irrelevant.

There is no trade, or unmerited contact with lesser species, they will be assimilated. Nobles are irrelevant. Economy is irrelevant. Solitary creatures that do not pose a notable threat to the Collective are not to be bothered with when there is important work to do. Corpses are to be vaporized or atom-smashed along with all other useless material. Cage traps should be common.

We are the Dorf. Lower your shields and surrender your booze. We will add your biological and technological reaction mats to our stockpiles. Resistance is canceled: Dangerous Terrain. You are caught in a pool of magma! You are melting! x18

World Domination

Pretend you are an evil mastermind. Now come up with some device or machine to render the world (or at least your portion of the map) totally unlivable, aside from, of course, your hidden lair.

You will receive bonus points for making a more realistic World Domination setup. Some suggestions:

Make one dwarf the evil mastermind. The evil mastermind will have no empathy whatsoever, and they will hate all other races, and put no value on the lives of his minions. Protect him at all cost. If he should die, switch his position to his oldest child (who will avenge his father, because insanity is hereditary.) or the most insane, diabolical dwarf in your fort or make a noble the evil mastermind. (everyone knows nobles are pure evil)
Impractical, overkill solutions to everyday problems ("Sir, the dungeon master wants a better room" "Well then turn his room into a tomb and flood it with magma, and do not bother me with such trivial matters again or I will have you shot.")
Give the evil mastermind a pet to obsess over. Give it a name like Mr. Bigglesworth or Snuggles. Even better if it's something really dangerous like a Giant Desert Scorpion.
Have a science lab. Use living creatures and people as test subjects.

Doomsday device suggestions:

Flood the map with water/magma (may require building walls around the edge of the map)
- BONUS: the water has carp in it.
  - BONUSMOD: Carp with frickin' laser beams attached to their heads.
Build an "Earthquake Machine" (the entire map is supported by a single support, which is connected to a lever)
Build an extensive holding cell network for "scientific purposes". Fill it with megabeasts and ~~elephants~~ ~~unicorns,~~ skeletal carp in secret. Have a lever that lets everything free to feed on the general population.
Embark in an evil area, and capture and tame all those undead animals ^{if possible} to create your own undead army
Bonus: Eliminate the dwarves who constructed your device before you set it off. They must not be allowed to warn the rest of the citizens.
Build an orbital weapons platform in space (which should be 12-15 stories above the ground, use your imagination), then arm it with magma bombs (droppable tank of magma) to glass the planet, rendering it uninhabitable for a few years.
Build a door (or hatch) in every space of your fortress. Have all the doors set to lock at the flip of a switch. Have the switch kill the person who pulls it. Give the nobility their toy.
Build Mechanical Volcano to flood entire map with searing magma.
do all of the above and link all the devices to one lever in the room of the king/queen

The Grand Treasury

At first, have the king come to you. Then excavate a laaarge room and fill it with i.e.: Lots of coins, shiny gems, artifacts, golden statues, silver mugs, etc. pp. But the king is still not satisfied with his possessions, so he wants more and more shiny and sparky things. Of course sooner or later (probably sooner) those filthy kobolds and goblins will come and try to steal this enormous hoard. We must never tolerate this! Turn your treasury into a strongroom like the world has never seen before! Secret doors, traps in abundance, guards at every door, ballistae, guard dogs, the whole program. If anything gets lost, you have proven your incompetence, and the king will have your fortress abandoned and founded another to guard his treasures.

Bonus: Build up the treasury and raid it successfully in Adventure Mode

Heaven

Build a dwarven version of heaven. Every dwarf must want to come to you! Important pieces:

Streets paved with gold.
The mindless hordes are held back by pearly gates -- or at least a close equivalent. Marble doors with diamond encrustations.
No dwarves die (except for criminals). Heaven is everlasting.
All criminals must be cast into the fires of Hell. Ideally, this would either be HFS or the bottom of a magma pipe.
Nothing is ever stolen. St. Peter doesn't screw up.
After the King has arrived, any male children he has must be sent out to fight sieges alone.

BONUS: No dwarves are ever unhappy -- no tantrums and no insanity.
BONUS: When migrants arrive at the pearly gates, view their thoughts and preferences and only allow those with a similar/same Diety as your population.
BONUS: Make Heaven 10 stories above the ground
Mod: Make Angel dwarves and a godly being. (suggestions: Cacame, Morul, Ironblood.)
ULTRABONUS: Make Heaven in the air, an earthly society on the ground (a wooden town perhaps?), and carve the HFS place into Hell, complete with a lake of Magma/fire.Look up the character of every dwarf and send him to the appropriate place.
MEGABONUS-(Re)Make: The Seven Seals have been broken and the Apocalypse arrives.

The Sky darkens (an obsidian ceiling spanning over the map).
Meteors (opened lava tanks and cave-ins) devastate the earth.
All bodies of water turn bloody.
Dig into the HFS and have a battle between Heaven and Hell.

City of Ember

Show those filthy humans that when dwarves build a secret underground refuge, they build to last! In other words, recreate Ember from the film "City of Ember" (yes, everyone is aware there is a book, that came first, an was part of a series), but do it right - none of these leaking pipes and crumbling buildings stuff, after only two and a half centuries underground!

Mine out a massive cavern multiple z-layers high , and build a human-style city underneath it instead of carving out various chambers.
You must seal it off. How long you wait to do this is up to you, but once it is sealed, you cannot unseal it for at least 200 years (if you decide to play that long). Ideally, use a utility to embark with a full set of dwarves (to represent the immigrating population) and seal the city off within one year of embarking.
Build individual houses with their own dining rooms and bedrooms. Multiple dwarves can live in one house, but usually only a single family will live in one house.
Build streets connecting all of the buildings, in the way that in the film, Ember didn't really have any space that wasn't either paved or built on until you got to the outskirts of the city.
Have a "greenhouse" out on the outskirts for farming.
You MUST have an underground river and use it for power.
You MUST have magma and use it for power.
Build City Hall, where the mayor has his office, with a nice fountain out front that actually works (probably involving water pressure, and as a testament to the fact that dwarves do it better, and their underground refuge isn't running desperately short of food, water, or power).
No military, because there is simply no need for one, but have a fortress guard (to function as police, basically).
After 200 or more years, unseal the city and colonize the surface.

BONUS: Instead of building your houses/other structures out of blocks or rocks, plan it all out beforehand and simply don't dig out the tiles that you want to be the walls of buildings, and smooth it all down so it looks the same, but your buildings are actually made out of solid natural rock.
BONUS: Actually cause some kind of catastrophe on the surface (flood it with magma or something) that makes it uninhabitable, to FORCE yourself to stay underground, but when you unseal the city after 200 years, the surface should have healed and be habitable again. So, don't do something permanent.

The quake

Make your entire forteress supported by one support.
on year 5, remove the support so your entire forteress drops one level.
Tell us the death rate.
double the height of the support every year, see how much is too much of a drop!

Pull A Boatmurdered

What's this? Too many goblins? Not enough fun? You may be needing excess amounts of lava!

Flood the entire map with water or lava
Maybe both and have an obsidian farm in the center
Pump all lava resources to the surface and watch it burn!

Most famously employed in Boatmurdered.

Hippie Exterminator

Much like trees, better water those elves.

It's a gigantic drowning chamber for Elves.
Construct a very long wall all the way around an Elf-village
Build a floor on top, sealing them in
Connect some screw pumps to this and the local water supply
Really processor intensive! Not for calculators!

At nothing else, at least build the box around your Trade Depot, and flood it when Elves are inside.
Drainage can be done with a floodgate to release the water from the depot.

Dwarven Arcology

Build your entire fortress above ground in one structure.
A subterranean level (the basement) on the bottom floor provides plump helmets, pig tails, and so on.
On the ground floor, grow above-ground plants and carve fortifications into all the walls.
Every other level is packed with food stores, refuse dumps, wood stockpiles, workshops, archery ranges, and bedrooms.
The only subterranean activity permitted is digging, although you may be able to get away with building your depot below ground.

Bonus: Cast the entire thing in Obsidian using magma and water and engrave all the sides with your greatness.

D For Dwarfdetta

Create the parliment building or some such construction
Rig it to explode or collapse spewing lava everywhere
Detonate the fortress while you play the 1812 overture somewhere
Time it to last 4 minutes, since that's how long the song is.

Bonus: make an underground railroad ( or magma pipe ) that detonates it. Bonus: make a metal statue at the top which gets exploded.

MegaBonus: send burning graphite or lignite flying into the (strangely always daytime) sky.

CosmicBonus: Have an important Dwarf in a coffin play a role in detonating it.

The Two Towers

Build a ring of stone [may be slightly difficult] and build a tower with four blades protruding from the top
Build a (much larger) tower with only two blades protruding from the top
Have the two towers combat each other without siege weapons

Bonus:

Rig the first one to flood and the second to explode! (and you only get the points if you've seen the movies and record the videos. Try to make the towers' destruction as close to the movies as you can!)

Twin maze of doom!

-Make a complicated maze pair where pressure plates on any floor will trigger the rapid death of everything one floor before that in the OTHER maze.

-Check what survives the ratrace longer: goblins or elves? Kittens or dogs?

-BONUS: make it self-cleaning so it can be reused over and over!

-Double bonus: make it flood the map with lava if anything ever reaches the end of their maze, meaning their victory is for all time - as well as the last thing the world will ever see before the end.

The doomsday temple of greed

1- Prepare a game with the poorest skills starting dwarves and nothing on embark.

2- Edit files to add a little castle with 10 switches, some of which open up to desirable stuff, or a mild trap. Have the lineup fairly obvious so people know which prize/trap pair they're going for.

3- After learning the principle and getting say a starting pick, 100 wood, 10 obsidian, 10 slade, freeing an angry elephant, an artifact crossbow, alcohol for 10 years, freeing a carp guarding the exit (simple enough puzzle, dig yourself another exit), getting an anvil and 7 bronze armor sets, and avoiding the one trap/prize which has a dragon... let them look up the stairs to the next bit on the next floor...

4- THIS floor has mild traps/good prizes again, but one of them frees 7 goblins AS WELL AS trigger an unnanounced very distant magma-flooding system of immense power and speed (they think the goblins are all there is to the trap, mwa ha ha). Make sure the slope means the greedy player will get what's coming at him fully...

5- Share this fun map without announcing what's on it. Surprise!!!

The Cathedral

Make an epically tall cathedral out of obsidian. Encrust it with gems, make multiple spires. Build giant stained-glass windows and make rows of chairs for pews. In niches high in the walls, place masterpiece or better statues, also encrusted and engraved. Underneath, make noble tomb catacombs. BONUS: Build it near a human/dwarf town. Kill heretics.

BONUS: Make several cathedrals, one to each in-game god. Once built, assign worshippers of a god to a burrow encompassing that god's cathedral. Build walls around each cathedral and let them fend for themselves.