Good Bad Bugs / Dwarf Fortress

Dwarf Fortress, due to its nature, has numerous, numerous Good Bad Bugs in its current release and has had many more in previous versions. For many players, bugs are half the fun of the game. Special mention goes to the following (some may be patched):

• The Mad Hammerer, one of the creator's favorite bugs. A Hammerer carries out death sentences by striking the prisoner with a hammer. If unable to wield a hammer (due to both arms being broken, for example), he would instead bite the subject to death and walk around with the person's bitten-off limbs in his mouth forever, until they started to rot.
• Toady's other favorite bug involved a farmer walking to a furniture stockpile, picking up a bed, then walking to a farm plot and planting the bed as if it were a seed. This was patched before release.
• Other bugs that tend to be mentioned nostalgically: infinite magma floods, serial killer elephants, the dwarves' utter indifference to being on fire. Note that all of these were part of the legendary Boatmurdered.
  • The "on fire" bug was particularly dangerous/hilarious when combined with a fortress's highly-volatile booze stockpile, which dwarves would regularly visit for a drink.
• You could also site your fortress overlapping with a human town... then proceed to undermine their buildings, causing them to collapse, and raid the rubble for fortress materials. Where this enters Good Bad Bug territory is the fact that the humans didn't care, and you could massacre their population, destroy their city, and steal the shattered remnants of their belongings without their losing the "Friendly" status.
• The absurdly overpowered throwing. A character could mangle a body part and brutalize enemies' internal organs with a pebble, a coin, or even vomit. A thrown Fluffy Wambler once decapitated a Bronze Colossus. Throwing was nerfed in 2011... which added the ability to pinch people's heads off.
• They can also bash enemies to death with their own pants, or fell someone with a well-thrown sock.
• "Tamed" animals that have killed dwarves in the past... aren't. They spend their time gleefully slaughtering the hairy ones, who still believe them to be tamed. The main way to stop this is to order the critter butchered as soon as you tame it, which gets you a lot of raw materials if it's something like a dragon or titan.
• There were also (sadly removed) bugs involving individuals ordering someone to hurt them — fortress mayors sentencing themselves to be beaten when their own mandates failed, and assorted folk in Adventure Mode requesting their own assassinations. The former was frequently exploited by players to eliminate mayors and nobles who made demands the fort had no way of fulfilling.
• The carp. Sweet Armok, the carp... A bug in the skill system meant anyone could buff up their stats by swimming. Seeing as they do that all the time, the carp became invincible monsters.

  ToadyOne: "I think I made the fish too hardcore."

  • While the carp have stepped down, giant sponges have taken up their mantle. Since the engine can't handle an unmoving animal properly and has some issues with determining the death of creatures without body parts or blood, they'll push your dwarves to death and are immune to normal weaponry. Even more ridiculously, examination of their raws indicates that they can be ridden on as war beasts, though nobody has reported any invaders using spongy mounts. The hilarious nature of the threat, along with its nigh-invulnerability, have made them nearly as famous as the carp of old. In later versions, the changes to blunt force mechanics renders them easily quashed with a few swings of a hammer, although they're still ludicrously overpowered.
    Without a nervous system, the only thing they can feel is ANGER.
• You can make magma-powered smelters out of ice.
  • Similarly, constructions of any type are completely invulnerable. Not only does this allow you to hold magma back with ice walls and wait out a forest fire inside a wooden building, it also means that a rampaging hellbeast that can smash whatever doors, floodgates, and bridges you put in its way will be stopped dead by a wall made of glass.
• "Artifacts" are the best products of craftsdwarfship, and are often adorned with a scene from the happenings in or around the fortress or from the procedurally generated history of the world in which it is set. But Planepacked is the best artifact ever: a giant monolith decorated in fine detail with the entire history of the world, including seventy-three depictions of itself!
• In the initial builds of the 2010 version, it was possible for animals and dwarfs to melt in the rain. What happened was that Dwarfs got covered in water and high temperatures will heat this water. This then caused the dwarf's fat (whose melting temperature was much lower than it should be) to melt off. Naturally, this being Dwarf Fortress, this was soon put to good use.
• A typical fort in the 31.10 version was less than 200 Z-levels tall. The ultimate metal, adamantine, is only found deep underground. An erratic bug in world generation resulted in a location having a 2200+ Z-level tower of adamantine shooting into the sky. Forum Thread
• Nothing exists off the edge of the map. You can't dig out the edge squares, but you can carve them into fortifications and drain a river off the map with them.
• Certain powerful enemies are rampant building destroyers, taking out floor hatches, floodgates, workshops, and anything else they can get their appendages on. If a door they'd like to wreck is jammed open, they will politely wait for it to close before doing anything at all.
• The danger room, where military dwarves are stuck in a room with training spears used in an upright spear trap hooked to a repeater. The spears are unable to actually hurt the armored dwarves but quickly give massive boosts to blocking and dodging as well as lesser boosts to weapons and armor skills.
  • Even more hilariously overpowered, the Shaft of Enlightenment glitch - any creature that falls at least two levels onto an upright spike/spear has a chance to do something that somehow gives them enough experience to make them about level 90 in several combat skills. For reference, the maximum visible level is 15 (Legendary) and the maximum achievable level in standard gameplay is 20. Players have chosen to interpret this as dwarves falling towards the earth and parrying it.
• A few materials, notably bituminous coal, lignite, and graphite, have an ignition point but no heat-damage point. Thanks to this and a quirk in the way items in containers are tracked, if you put some in a bin and light it on fire, it will burn for over 9 months and cannot be extinguished. You can drain an entire ocean into a bin full of burning lignite.
• If pieces of wall/floor fall into liquid due to a cave-in, liquid displacement is simulated by vertically teleporting the displaced liquid to the nearest empty space. Players have taken advantage of this to create the "magma piston": a hundred level (or more) high stone column carved out of the earth and made to fall into a pool of magma, causing the magma to teleport up a hundred levels.
  • This, along with bugs like the ability to store an infinite amount of stone on one square if you mark it as a dump site, is such a savings in time, energy, and not-killing-your-frame-rate that some players don't even consider it an exploit.
• Things get really hilarious if there are duplicate raw entries after modding. You can end up with mysterious, typeless "meat", the extinction of the turtle, wagon eggs and even a fortress where instead of dwarves, you start out with extremely dwarfy elves... or, perhaps, ducks. With duplicate raws, all bets are off.
• The affectionately named "Dwarven Atom Smasher" exploit. It causes anything to disappear without a trace if it's smashed by a drawbridge when it goes down. This has become something of an Ascended Glitch, to the point where the developer has added Contractual Boss Immunity to this on some of the more powerful monsters.
• Heat usually doesn't kill you by burning, it does it by melting your fat. This has led to a bug where if all the fat is melted off of a character without them dying (surprisingly actually easier done than it sounds) they become effectively immune to fire long-term.
• Vampires don't need any sleep, food or water, but they still count as members of your civilisation. It only took a short amount of time for players to figure out that if you brick vampires into the walls of your fortress they make it effectively immortal, as long as they don't go insane.
• Version 0.40, while adding tons of amazing new features, also introduced a number of hilarious bugs along with it (some of which have already been fixed):
  • Children born throughout the world appear on the unit list for your own fortress, resulting in an apparent Wave of Babies in the unit list (and random crashes when it tries to highlight them on the minimap).
  • Talking to an unconscious (or unintelligent) creature allows you to carry on a conversation with yourself.
  • Otherwise peaceful goblins in Human marketplaces immediately start brawling once you show up.
  • If you get ambushed by a wild creature while with a companion who doesn't like you very much, said companion might decide to side with the wild animal and engage you in lethal combat (because that's what the animal was doing). In the words of Toady One, "there's a fight (scared animal)! animal? neutral. but I hate that guy! let's jump in on the side of the animal! no quarter? no problem!"
• The dev log itself is worthy of curation; some of the best bugs get fixed before release, but Toady has the grace to tell us about them anyhow. While emotions were being revised in February 2014, this log was posted: "Today's success was to have a crying mother spit on me and call me a murderer, so that's where we're at. Of course, people familiar with modding or magma crabs might guess that the first time she spit at me, the glob came out frozen and my murderous character, being handy with a sword, batted the saliva ice cube out of the park."
• With 0.42's release:
  • The ensuing taverns, a possible bug resulted in cats getting drenched in dwarven booze if they came anywhere near a tavern. Then the unfortunate critter cleans itself with its tongue and dies horribly. This was because the amount of liquid in "a splash" wasn't specified, so each splash was actually an entire pint, resulting in the cat ingesting the gallons and gallons of alcohol potentially spilled on it from a short walk through a bar.
  • 0.42 brought procedurally generated instruments to play music with, among which are crimes against reality that somehow have hundreds of pipes despite being perfectly portable. A regular accordion only has ten. You can also get musical instruments that consist only of a bowl, or a bar of tin, but your dwarves will continue playing it and somehow making sound anyway.
  • In 0.42, Adventurers can hand out drinks to NPCs, whom are all too willing to chug anything you give them. Emphasis on anything. So long as it's in a mug, they'll gladly down things like vomit, whole watermelons, stacks of weapon, hell, even the corpses of their former friends. One can even put two caged cats in a sack and stuff that in a mug and they'll drink it (or if you're feeling particularly evil, you can make them drink themselves by offering them the cage they're in; the game can only offer a "[victim] has died in a cage".)
• The game handles injuries to the neck rather strangely when they happen during worldgen. As in it doesn't seem to immediately realize you can't live with a missing neck. These mysteriously headless people then proceed to live their lives with no problem until they arrive at your fortress/meet your adventurer, at which point the game realizes its mistake and they promptly drop dead. Something similar tends to happen with dwarves past their age of death, as they will die the exact second they enter your map. This bug also manifests in lesser ways with people wearing gloves or boots on limbs they lost years ago.
• It is possible for your trade posts to spontaneously explode because people turn up to trade carrying bags of magma. This is possibly the dwarfiest bug known to man, elf, or short bearded alcoholic.
• Early versions of 0.42 had enormous numbers of horses, and only horses, roaming all over the place. 3600 horses in a small hamlet was fairly common, and there were several settlements that consisted of one goblin and thousands of horses.
• In early 0.43, chopping down trees in the object testing arena revealed the Minus World around it, which many players were keen on exploring.
• One that comes and goes stems from the relatively minor bug that causes contaminants to stay airborne forever if knocked into the air by anything (say, a cave-in). Problem is, sapling spawning only reads tiles for mud presence, with no regard for whether there is any floor or not. Thus, saplings start growing on the floating mud, until they grow enough for the game to actually check and realize they're floating in mid-air, and brings the tree crashing down like a ton of rock, crushing individuals and punching holes in roofs like a regular cave-in. And yet the mud stays there, letting the cycle begin again and ensuring your fort'll be bombarded with respawning meteor trees until you get rid of the mud.
• If, at any point, a minecart actually falls rather than just descending, an odd effect will happen where the actual impact will be taken on the floor right below the impacted one, no matter what was on it. The community quickly used this as a sort of phantom-force piston trap, with constant falling minecarts on the floor above a hallway constantly striking trespassers below.
• While the 0.4x versions have made sparring work properly and has made training dwarves a lot easier, it also added a particularly strange bug where sparring dwarves (and only sparring, regular battles don't have this) occasionally dodge in ways reality shouldn't allow and end up teleporting through walls and floors (which does mean dwarves can accidentally dive through a wall and into a volcano). While annoying, there's something a little amusing about it.
• For a time, animals were given a few too many sentient traits without actual sentience, and as such, you had animals that had needs, which went unfulfilled because they're animals and thus they got terminally distracted and slowed down all activities because of it. Worse, some of their needs revealed the animals worship Gods of their civilization, and try to pray to them in temples but realize they're animals and can't pray, thus being unable to fulfill that need. Even worse, animals in your tavern could actually reveal the location of various artifacts around the world and in the fortress to visitors, somehow getting their locations across without speaking. And worst of all, in Worldgen, any animal that becomes a historical figure can actually start acting like a sentient under certain circumstances, so you can occasionally spot Saltwater Crocodile Recruits going around cities, getting bursts of civilized behavior before remembering they're animals and going savage again, including mauling residents of the cities they just civilizedly moved into.
• Certain bugs with citizen petitions (specifically, accepting petitions post-mortem) can lead to unusually interactive ghosts that can even be recruited into squadrons and try to spar with the other soldiers but keep finding out it's pointless when you're completely intangible, and since they aren't programmed to actually fight just tend to hang around the enemy being harmlessly spooky while any attacks made against them do absolutely nothing. Sending them on raids, however, will turn them into deadly threats as the game forgets ghosts can't touch.
• While certain civilizations deciding leaders through contests is intended, and weapon-throwing contests being among these was also very much intended, a minor oversight caused some of these to include crossbow-throwing contests to decide who gets to lead a nation.
• The Necrobacon bug/exploit, which takes advantage of how strength buffs translate directly to muscle mass and how corpses risen by necromancers tend to get pretty hefty strength buffs. It's like a dwarf-made GMO.
• Falling items are calculated strangely, in that density and surface area interact in strange ways. Large objects falling don't cause as much harm as they should and small things, such as picked plants, clothing, coins and seeds become absurdly harmful. While annoying when a dwarf falls into your garbage chute and dies because they got their lungs busted by a falling -cave spider silk sock-, if you have a whole stack of coins and seeds and a retracting bridge on a repeater to scatter them around you can generate a large killzone where any foes will be pelted to death by tiny items that somehow hit them like shrapnel.
• While the "melting" has been fixed, another bug causes dwarves to get extreme mood swings from rain, leaving deep psychological scars and fundamental changes in their worldview; we're talking about "lost all will to live after being in open air for a single turn" levels of trauma. Players of course interpret this as Dwarves hating the natural world to the point that even touching a few droplets drives them angry, depressed or insane... or all three. Others blame it on elves, because rain is natural, and elves love everything natural.
• In adventure mode, if you attack an opponent with a stack of items, each item in the stack hits the attacked body part individually, dealing the same amount of damage each time. As a result of this, one can go around destroying enemies with stacks of lettuce, raw meat or other every-day objects.
• Only hours after the villain update (0.47) released, players started reporting a bug that would cause the game to crash during world gen. The bug? Mountains trying to make music, only to fail since they have no instruments and cannot speak.
  • A recursive bug as well, as the exception used the biomes as biwords for species. It was actually mute dwarves lacking instruments. That it could get so hilariously mangled is itself a Good Bad Bug.
• Also in 0.47.01 is a glitch where babies are no longer carried by their mothers, but ride them. As in, like mounts, complete with steering them. The pair would eventually starve since babies have zero survival instinct and no concept of where to go, so they'd just steer their mums around randomly until death.
• There are flying lungfish, to the bewilderment of many players.
• Thieving creatures can steal stepladders while dwarves are using the things. This would result in the dwarf hanging in midair, since they were unable to use the stepladder to climb down. The game would only remember that gravity is supposed to exist if another dwarf approached, leading to the trapped dwarf suddenly falling.
• A bug caused the "fled due to suspicion over their lack of aging" to fire in a necromancer's own tower. Thus making necromancers appear to have severe social anxiety.
• Yet-unknown bugs that ramped up slightly with the Steam release can cause children who somehow have negative age and birthdays that are yet to come. These children show up headless in the graphical version despite technically having everything, and in past occasions were impossible to hit because they were too small (possibly negative in size). Once the negative years have passed, these paradox children just start working normally.
• When you take up the game's offer for a tutorial fortress, the embarking process is done for you, including picking the location. It checks for many parameters like wood and ore availability to ensure it's a relatively easy one... But forgets to check for others like regional threats. It's not uncommon for the game to embark you so deep into the Evil-corrupted territory of a Necromancer tower that Experiments just walk around freely like normal widllife and you're getting sieged by walking corpses (hardcore threats that need experience to handle) before you even have your first caravan; the tutorial just keeps trying to tell you how trading works like nothing is happening while the caravan can't even arrive/is actively being killed by undead. This would be annoying if it weren't such a perfect illustration of what kind of game this is. WELCOME TO THE TUTORIAL LEVEL indeed.
• Once you have a justice system set up and some open cases to pursue, you can actually interrogate the dead. Your Captain of the Guard will head to the spot in which they died and drag seemingly nothing to their office for interrogation. And not only do the dead answer, they seem even more susceptible to Perp Sweating when interrogated and immediately spill every bean they have. Sure, it's cheating, but with the troubles of the Justice system as it is and with you (currently) unable to send some agents into the world to grab the usual artifact-thieving bastards and drag them back to your fort for a little Dwarven Justice, it's tempting to just kill the suspicious and interrogate their spirits to know what's going on.
• In the Steam version, glass floors are transparent and show you what's right under them in real time... this happens even if you build a glass floor directly onto the raw earth, somehow X-raying through solid rock to show you what lies beneath. This can be a very useful trick when you're trying to avoid magma or worse things while digging for valuables.