|This article is about the current version of DF.|
A syndrome is a disease or effect that a poor, helpless creature might get through encountering certain other creatures, extracts, or supernatural weather. They generally cause unpleasant and frequently fatal symptoms over a short to long period of time, but some will clear up over time or with the assistance of a doctor. A Hospital is required to diagnose and potentially treat the syndrome.
List of syndromes
|Syndrome||Venom||Acquired||Short-term Symptoms||Long-term Symptoms||Chronic Symptoms|
|Adder bite||adder venom (injected)||Being bitten by an adder, giant adder or adder man||Strong pain||Swelling
|Bark scorpion sting||bark scorpion venom (injected)||Being stung by a bark scorpion, giant bark scorpion or bark scorpion man||Strong pain||None||None|
|Black mamba bite||black mamba venom (injected)||Being bitten by a black mamba, giant black mamba or black mamba man||Dizziness
|Blob blisters||cave blob fluid
(contact or ingested)
|Touching a cave blob||Mild pain
|Brown recluse spider bite||brown recluse spider venom (injected)||Being bitten by a brown recluse spider, giant brown recluse spider or brown recluse spider man||Nausea
|Severe localized necrosis||None|
|Bumblebee sting||bumblebee venom (injected)||Being stung by a bumblebee worker||Pain
|Bushmaster bite||bushmaster venom (injected)||Being bitten by a bushmaster, giant bushmaster or bushmaster man||Strong pain
|Cave floater sickness||cave floater gas
(inhaled or ingested)
|Expelled from cave floater||Mild nausea||Fever
Strong drowsiness (delayed)
Strong dizziness (delayed)
|Cave spider bite||cave spider venom
|Being bitten by a cave spider||None||None||Very mild dizziness|
|Copperhead snake bite||copperhead snake venom (injected)||Being bitten by a copperhead snake, giant copperhead snake or copperhead snake man||Pain
|Giant cave spider bite||giant cave spider venom
|Being bitten by a giant cave spider||Size-dependant paralysis.||Death by asphyxiation, in small targets. Large targets are generally unhindered...unless you count the high probability of being eaten by the giant cave spider as a hindrance.||None, not that it really matters.|
|Gila monster bite||gila monster venom (injected)||Being bitten by a gila monster, giant gila monster or gila monster man||Pain
(contact, inhaled, injected, or ingested)
|Purposely exposing oneself to the extract. Only affects mountain gnomes and dark gnomes.||None||Severe systemic necrosis2||None|
|Giant desert scorpion sting||giant desert scorpion venom
|Being stung by a giant desert scorpion||Necrosis of the brain and nervous system||Certain death||None, not that it really matters.|
|Helmet snake bite||helmet snake venom
|Being bitten by a helmet snake||Minor bleeding||Fever
Intense localized necrosis
Possible loss of limb
|Honey bee sting||honey bee venom (injected)||Being stung by a honey bee worker||Pain
|Inebriationv0.42.01||Alcohol (consumed/injected)||Consuming alcoholic drinks||Nausea
|Iron man cough||iron man gas
|Expelled by iron man||Coughing blood||None||None|
|King cobra bite||king cobra venom
|Being bitten by a king cobra||Complete paralysis1
Pain, dizziness, drowsiness
|Phantom spider bite||phantom spider venom
|Being bitten by a phantom spider||None||Numbness and mild dizziness||None|
|Platypus sting||platypus venom
|Being kicked by a platypus, giant platypus or platypus man||Pain and swelling||Extreme pain, swelling possibly to the point of necrosis||None|
|Rattlesnake bite||rattlesnake venom
|Being bitten by a rattlesnake, giant rattlesnake or rattlesnake man||Pain, nausea, blisters, swelling, bruising||Severe localized necrosis||None|
|Serpent man bite||serpent man venom
|Being bitten by a serpent man||Complete paralysis1||None||None|
|Mummy's curse||Disturbance interaction.||Being cursed by a mummy, when caught raiding their tombs||None||None||20% chance of any skill roll failing, regardless of skill.|
|Vampirism||Divine Curse.||Drinking the blood of a vampire. Toppling statues in shrines in Adventure Mode or temples in Dwarf Mode (random chance).||None||None||Victim becomes a vampire.|
|Werebeast Curse||Divine Curse.||Being bitten by a werebeast. Toppling statues in shrines in Adventure Mode (random chance).||None||None||Victim becomes a werebeast.|
|Necromancy||Divine Curse.||Reading a book/slab that contains the secrets to life and death.||None||None||Reader becomes a Necromancer.|
|[evil rain] sickness3||Random||Being caught outside in freakish weather in an evil biome||Random||Random||Random|
|[evil cloud] sickness4||Being caught in a creeping cloud in an evil biome|
|beast sickness5||Encounters with forgotten beasts|
|titan sickness5||Encounters with titans|
|night sickness5||Encounters with werebeasts|
|demon sickness5||Encounters with demons|
|divine sickness5||Encounters with angels|
- 1. For small creatures such as humans and dwarves, paralysis tends to result in suffocation.
- 2. Necrosis of the brain will eventually result in death once the brain rots away completely.
- 3. Evil rain typically only causes minor symptoms such as blisters, bruising, coughing blood, dizziness, fever, nausea, oozing, and pain.
- 4. Evil clouds either cause major symptoms (as with beast/titan/demon sicknesses) or permanently transform creatures into zombie-like forms.
- 5. Titans, forgotten beasts, werebeasts, demons and angels have a chance to have a randomized syndrome. These range from pointless (mild blisters from inhaling boiling blood) to instantly fatal (severe necrosis from a contact poison attached to a breath weapon/creature made of blood).
The anatomy of a syndrome
Mechanically, syndromes are bundles of tokens attached to a material (or to an interaction effect; see below) - they're confined to creature materials in vanilla DF, but it's a simple matter to add them to inorganic materials. When the material is injected, touched, inhaled, or ingested (depending on the syndrome), the creature suffers the predations of a nasty disease or poison. Here's an example syndrome, taken from the Giant Cave Spider raws.
If you are having troubles getting the syndromes to work (i.e., in combat reports, getting "supersnake n/a splatters~etc"), then simply throw the venom template into the actual creature's raw, which is what the LOCAL_CREATURE_MAT actually calls on; the venom being in the same file.
[USE_MATERIAL_TEMPLATE:VENOM:CREATURE_EXTRACT_TEMPLATE] [STATE_NAME:ALL_SOLID:frozen giant cave spider venom] [STATE_ADJ:ALL_SOLID:frozen giant cave spider venom] [STATE_NAME:LIQUID:giant cave spider venom] [STATE_ADJ:LIQUID:giant cave spider venom] [STATE_NAME:GAS:boiling giant cave spider venom] [STATE_ADJ:GAS:boiling giant cave spider venom] [PREFIX:NONE] [ENTERS_BLOOD] [SYNDROME] [SYN_NAME:giant cave spider bite] [SYN_AFFECTED_CLASS:GENERAL_POISON] [SYN_IMMUNE_CREATURE:SPIDER_CAVE:ALL] [SYN_INJECTED] [CE_PARALYSIS:SEV:100:PROB:100:RESISTABLE:SIZE_DILUTES:START:5:PEAK:10:END:20]
The first line, USE_MATERIAL_TEMPLATE, is creating a new material, called POISON, using the CREATURE_EXTRACT_TEMPLATE as the basis. After this, the STATE_NAME and STATE_ADJ tokens are used to define the names and adjectives assigned to different states of the material - GAS, LIQUID and ALL_SOLID, in this case, though ALL is also a valid token. At this stage, you can use any material tags like MAT_FIXED_TEMP or similar to set further material properties, though this usually isn't necessary.
This tag determines whether a poison enters the blood or not. If it is not included, the poison will splatter (if liquid) or flow (if gas) over the affected body part instead when injected. If you're using a contact poison, leave this out. Necessary for injected poisons.
This tag ends the material details and begins the definition of the actual syndrome.
This one is self-explanatory - the name of the syndrome as it will appear in-game.
This token defines what CREATURE_CLASS will be affected by the syndrome. Most creatures are classed under GENERAL_POISON. Multiple tokens can be used in a single syndrome.
As above, but makes class immune.
This token defines which creatures CANNOT be affected by the syndrome - useful for addressing specific instances within a population, such as a specific caste or an individual creature that falls under GENERAL_POISON. Syntax is [SYN_IMMUNE_CREATURE:creature:caste]. ALL can be used for the caste.
As above, but makes creature or caste susceptible.
This tag sets a class for the syndrome that can be used in interactions.
Similar to SYN_CLASS, this sets an identifier that can be shared between multiple syndromes, for use with the SYNDROME_DILUTION_FACTOR creature token. In vanilla DF, this is used to allow dwarves to drink more alcohol before becoming inebriated.
Probably prevents affected dwarves from being carried to the hospital.Verify
Repeated exposure to the syndrome will result in the effects becoming more intense. In vanilla [SYN_CONCENTRATION_ADDED:100:1000] is used with alcohol.
SYN_INJECTED, SYN_CONTACT, SYN_INHALED, SYN_INGESTED
This token determines the method of infection - injected syndromes must be injected via a creature attack, while contact syndromes result from any contamination of a creature by material splatter (such as blood), inhaled syndromes must be inhaled in gaseous form (such as from boiling or a creature breath attack), and ingestion syndromes must be eaten or drunk. Any combination of these tags can be used. A fun variation on the usual creature injection routine is to create a material with a SYN_CONTACT syndrome and have a creature use it for blood - this tends to end poorly for any predator that chooses to attack them.
This is one method for getting a poison into a creature. If [ENTERS_BLOOD] is applied, it will be injected into the bloodstream. Otherwise, it will just splatter over the area. Put this on a creature attack. Substance type (gas, liquid, solid) does not appear to have an effect. The numbers on the end are minimum and maximum.
CE_X, or creature effect tokens, are the real meat and bones of your syndrome. They're detailed below.
Creature effect tokens
Each and every syndrome has a number of creature effect tokens, represented by CE_X - these lovely little beauties determine exactly how the poor creature suffering from the syndrome is affected. An example CE token is as follows:
In this example, we have an effect that will always cause severe necrosis in whichever bodypart it touches, so long as that bodypart is vascular and that the creature is not able to resist it in some manner. The effect begins shortly after the syndrome is contracted, peaks 1000 time units afterwards, and finally ceases another 1000 time units later.
As a general rule of thumb, so long as CE_X starts the string and START/(PEAK/END) end it, the order of the intervening tokens isn't important. PEAK and END aren't required.
The effect type. This can be a number of different tokens, as detailed in the table below this list.
The severity of the effect. Higher values appear to be worse, with SEV:1000 CE_NECROSIS causing a part to near-instantly become rotten.
The probability of the effect actually manifesting in the victim, as a percentage. 100 means always, 1 means a 1 in 100 chance.
- LOCALIZED (Overwrites BP tokens)
This tag causes an effect to ignore all BP tokens and then forces the game to attempt to apply the effect to the limb that came into contact with the contagion - i.e. the part that was bitten by the creature injecting the syndrome material, or the one that was splattered by a contact contagion. If an effect can not be applied to the contacted limb (such as IMPAIR_FUNCTION on a non-organ) then this token makes the syndrome have no effect. This token also makes inhaled syndromes have no effect.
- BP:BODY_PART:TISSUE (Overwritten by LOCALIZED)
Specifies which body parts and tissues are to be affected by the syndrome. BODY_PART can be BY_CATEGORY:x to target body parts with a matching [CATEGORY:x] body token (or ALL to affect everything), BY_TYPE:x to target body parts having a particular type (UPPERBODY, LOWERBODY, HEAD, GRASP, or STANCE), or BY_TOKEN:x to target individual body parts by their ID (as specified in the [BP] token). For example, if you wanted to target the lungs of a creature, you would use BP:BY_CATEGORY:LUNG:ALL. The syndrome would act on all bodyparts within the creature with the CATEGORY tag LUNG and affect all tissue layers. For another example, say you wanted to cause the skin to rot off a creature - you could use BP:BY_CATEGORY:ALL:SKIN, targeting the SKIN tissue on all bodyparts. Multiple targets can be given in one syndrome by placing the BP tokens end to end. This is one of the most powerful and useful aspects of the syndrome system, as it allows you to selectively target bodyparts relevant to the contagion, like lungs for coal dust inhalation, or the eyes for exposure to an acid gas. Not everything takes a target!
- VASCULAR_ONLY (Optional)
This syndrome only affects tissue layers with the VASCULAR token.
- MUSCULAR_ONLY (Optional)
This syndrome only affects tissue layers with the MUSCULAR token. Are you seeing a trend here?
- SIZE_DILUTES (Optional)
This token presumably causes the effects of the syndrome to scale with the size of the creature compared to the size of the dose of contagion they received, but has yet to be extensively tested.
- SIZE_DELAYS (Optional)
As above, this token has yet to be tested but presumably delays the onset of a syndrome according to the size of the victim.
- DWF_STRETCH:Xv0.42.01 (Optional)
Multiplies the duration of the syndrome by X in Fortress mode. If X is 72, syndrome will last the same amount of ticks in fortress and adventure mode.
- ABRUPTv0.42.01 (Optional)
Makes the symptom begin immediately rather than ramping up.Verify
- CAN_BE_HIDDEN (Optional)
- RESISTABLE (Optional)
Determines if the effect can be hindered by the target creature's disease resistance attribute. Without this token, disease resistance is ignored.
The details of this table are still being thrashed out by modders, so if you have anything to add, please don't hesitate to hit the edit button!
Non-targeted syndromes will ignore any BP tokens and LOCALIZED tokens.
|CE_BLEEDING||Yes||Causes the targeted bodypart to start bleeding, with heavy enough bleeding resulting in the death of the sufferer. Some conditions seem to cause bleeding to be fatal no matter how weak.|
|CE_BLISTERS||Yes||Covers the targeted bodypart with blisters.|
|CE_BRUISING||Yes||Causes the targeted bodypart to undergo bruising.|
|CE_IMPAIR_FUNCTION||Yes||An organ afflicted with this CE is rendered inoperable - for example, if both lungs are impaired the creature can't breathe and will suffocate. This token only affects organs, not limbs. Note that this effect is currently bugged, and will not "turn off" until the creature receives a wound to cause its body parts to update.|
|CE_NECROSIS||Yes||Causes the targeted bodypart to rot, with associated tissue damage, miasma emission and bleeding. The victim slowly bleeds to death if the wound is not treated. Badly necrotic limbs will require amputation.|
|CE_NUMBNESS||Yes||Causes numbness in the affected body part, blocking pain. Extreme numbness may lead to sensory nerve damage.|
|CE_OOZING||Yes||Causes pus to ooze from the afflicted bodypart.|
|CE_PAIN||Yes||Afflicts the targeted bodypart with intense pain.|
|CE_PARALYSIS||Yes||Causes paralysis. Paralysis is complete paralysis and will cause suffocation in smaller creatures. Paralysis on a limb may lead to motor nerve damage.|
|CE_SWELLING||Yes||Causes the targeted bodypart to swell up. Extreme swelling may lead to necrosis.|
|CE_COUGH_BLOOD||No||This effect results in the sufferer periodically coughing blood, which stains the tile they're on and requires cleanup. It doesn't appear to be lethal, but may cause minor bleeding damage.|
|CE_DIZZINESS||No||Inflicts the Dizziness condition, occasional fainting and a general slowdown in movement and work speed.|
|CE_DROWSINESS||No||Causes the Drowsiness condition.|
|CE_FEVER||No||Causes the Fever condition.|
|CE_NAUSEA||No||Causes the Nausea condition, and heavy vomiting. Can eventually lead to dehydration and death.|
|CE_VOMIT_BLOOD||No||This effect results in the sufferer periodically vomiting blood, which stains the tile they're on and requires cleanup. It doesn't appear to be lethal, but may cause minor bleeding damage.|
|CE_ERRATIC_BEHAVIORv0.42.01||No||Causes erratic behavior, meaning "People that like to brawl have a chance of starting a brawl-level fight with any nearby adult" -Toady|
Starting with DF version 0.47.01, there are healing counterparts to most of the tokens above that will heal various syndrome effects or physical damage.
|CE_STOP_BLEEDING||Yes?||Decreases the severity of the bleeding of any wounds or syndrome effects on the targeted bodypart. The SEV value probably controls by how much the bleeding is decreased.|
|CE_CLOSE_OPEN_WOUNDS||Yes?||Closes any wounds on the targeted bodypart with speed depending on the SEV value.|
|CE_HEAL_TISSUES||Yes?||Heals the tissues of the targeted bodypart with speed depending on the SEV value.|
|CE_HEAL_NERVES||Yes?||Heals the nerves of the targeted bodypart with speed depending on the SEV value.|
|CE_REDUCE_PAIN||Yes?||Decreases the severity of pain produced by wounds or syndrome effects on the targeted bodypart. The SEV value probably controls by how much the pain is decreased.|
|CE_REDUCE_SWELLING||Yes?||Decreases the severity of swelling on the targeted bodypart.|
|CE_CURE_INFECTION||Yes?||Probably decreases the severity of the infection from infected wounds over time.|
|CE_REDUCE_PARALYSIS||Yes?||Decreases the severity of any paralysis effects on the targeted bodypart.|
|CE_REGROW_PARTS||Yes||Causes missing bodyparts to regrow. SEV controls how quickly bodyparts are regrown|
|CE_REDUCE_DIZZINESS||No||Decreases the severity of any dizziness the creature has.|
|CE_REDUCE_NAUSEA||No||Decreases the severity of any nausea the creature has.|
|CE_REDUCE_FEVER||No||Decreases the severity of any fever the creature has.|
Several special syndrome effects take different arguments than the above. These are used for generated interactions in unmodded games, but may be used as well for any substance or custom interaction.
|CE_ADD_TAG||No||tags||Adds a tag to the affected creature. Many arguments can be used sequentially within one syndrome token. Valid tags are the same as that of the interaction token IT_REQUIRES, ie.
BLOODSUCKER, CAN_LEARN, CAN_SPEAK, CRAZED, EXTRAVISION, LIKES_FIGHTING (or LIKESFIGHTING), MISCHIEVOUS (or MISCHIEVIOUS), NO_CONNECTIONS_FOR_MOVEMENT, NO_DIZZINESS, NO_DRINK, NO_EAT, NO_FEVERS, NO_PHYS_ATT_GAIN, NO_PHYS_ATT_RUST, NO_SLEEP, NO_THOUGHT_CENTER_FOR_MOVEMENT, NOBREATHE, NOEMOTION, NOEXERT, NOFEAR, NONAUSEA, NOPAIN, NOSTUN, NOT_LIVING, NOTHOUGHT, OPPOSED_TO_LIFE, PARALYZEIMMUNE, SUPERNATURAL, TRANCES, NO_AGING, STERILE, UTTERANCES.
|CE_REMOVE_TAG||No||tags||Removes a tag from a creature. Supported arguments are the same as CE_ADD_TAG.|
|CE_DISPLAY_TILE||No||TILE:tile number:colour||The creature displays the specified tile and colour instead of its normal one.|
|CE_DISPLAY_NAME||No||NAME:singular:plural:adjective||Attaches a specified name to the creature's normal name.|
|CE_FLASH_TILE||No||TILE:tile number:colour:FREQUENCY:ticks default tile:ticks syndrome tile||The creature flashes between its normal tile and the one specified here.|
|CE_PHYS_ATT_CHANGE||No||Attribute:percentage:fixed boost(?)||Alters the physical attributes of a creature.|
|CE_MENT_ATT_CHANGE||No||Attribute:percentage:fixed boost(?)||Alters the mental attributes of a creature.|
|CE_BODY_APPEARANCE_MODIFIER||No||APPEARANCE_MODIFIER:HEIGHT/LENGTH/BROADNESS:percentage(?)||Alters the size of the creature.|
|CE_BP_APPEARANCE_MODIFIER||Yes||body part:APPEARANCE_MODIFIER:attribute:number]||Alters the characteristics (height, width etc.) of a body part.|
|CE_MATERIAL_FORCE_MULTIPLIER||No||MAT_MULT:material:A:B||Makes creature affected by materials more or less by a factor of A/B. If A is 3 and B is 2, the creature will be 1.5x weaker to the defined material (can be NONE:NONE for all); if 2:3, the creature will be 1.5 times stronger.|
|CE_BODY_MAT_INTERACTION||No||Causes one of the creature's materials to trigger an interaction, generally when ingested. Several additional tokens may be specified after this:
|CE_SPEED_CHANGE||No||speed modifier:number||Changes the speed of a creature.
Speed modifier contains one or both of:
The minimum and maximum speeds able to be created by CE_SPEED_CHANGE are 99 and 10,000 respectively.
|CE_CAN_DO_INTERACTION||No||Makes the creature able to perform an interaction. See Interaction token. To specify the interaction, use the argument:
|CE_SPECIAL_ATTACK_INTERACTIONv0.47.01||Yes||INTERACTION:<interaction name>:BP:<selection criteria>:<name of category,type, or token of designated part/parts>||Makes the creature able to perform an interaction when using an attack with a designated body part/parts. See below for an example|
|CE_BODY_TRANSFORMATION||No||PROB:percentage:START:time:END:time||Transforms into another creature. PROB and END arguments optional. The target creature is specified with further tokens:
Note that any wounds the creature has suffered will instantly heal upon transforming, both into and out of the target form. Undead limbs of a creature with this token will grow into a full instance of that creature.
|CE_SKILL_ROLL_ADJUST||No||PERC:percentage:PERC_ON:percentage||Alters the skill level of a creature. The argument PERC specifies a percentage of the creature's current skill, and PERC_ON the probability of the effect being applied on a particular roll.|
|CE_SENSE_CREATURE_CLASS||No||START:time:CLASS:creature class:tile:color||Allows creature to see other creatures with given class through walls. Vampires, for example, have START:0:CLASS:GENERAL_POISON:15:4:0:1.|
|CE_CHANGE_PERSONALITYv0.42.01||No||FACET:trait:amount||Changes a personality trait by amount. Multiple FACET:trait:amount sets may be used.|
|CE_FEEL_EMOTIONv0.42.01||No||EMOTION:emotion||Makes the creature feel a specific emotion; severity based on standard SEV value. The thought the creature receives is: "[creature] feels [emotion] due to [syndrome name]". See Emotion for the list of valid emotions.|
All creature effect tokens take START, END and PROB numbers, and can be followed by [CE:PERIODIC] and/or [CE:COUNTER_TRIGGER] to restrict when they actually take effect.
Currently, the only valid period type is MOON_PHASE.
Valid counter values are below:
|ALCOHOLIC||How long it's been (in time units) since the creature last had a drink of alcohol. Only present on creatures who need alcohol to get through the working day.
|CAVE_ADAPT||How cave-adapted the creature is. Increases by 1 for every time unit spent underground, to a maximum of 800000.
|PARTIED_OUT||How long before the creature will decide to attend another party. Starts at 3+ months and counts down to zero.|
|MILK_COUNTER||How long before the creature can be milked again. Starts at the creature's MILK frequency and counts down to zero.|
|EGG_SPENT||How long before the creature can lay more eggs. Starts at 3 months and counts down to zero.|
|GROUNDED_ANIMAL_ANGER||How angry (and likely to attack) an animal is from being over-crowded. Increases when over-crowded and otherwise counts down to zero.|
|TIME_SINCE_SUCKED_BLOOD||How long it's been (in time units) since the creature last sucked somebody's blood.|
|DRINKING_BLOOD||How much longer the creature will be drinking somebody's blood. Starts at 2.4 days and counts down to zero.|
|MOD||This page includes mods. The content is not part of normal DF as released. Changing game files can sometimes cause unexpected results, and should always be done with care and caution.|
Inorganic syndromes and you!
It's perfectly possible - and quite simple - to add a nasty syndrome to a type of rock or metal - you simply add the syndrome tokens to the material definition in the same manner that you would add them to a creature material definition. The only catch is that since your hapless dwarves will only normally encounter the material in metal, gem or boulder form, a bit of creativity must be used to actually get them inside your citizens - that is, you need to make them 'explosively boil' as soon as they're mined or produced. This has the sad side effect of destroying the actual item - sorry, no highly radioactive uranium this release.
The easiest way to accomplish this is to assign the material a low boiling point, usually just under room temperature, and make sure its temperature is fixed to a point above it.
[MELTING_POINT:NONE] [BOILING_POINT:10000] [MAT_FIXED_TEMP:10001]
Now, as soon as this substance hits the open air - by being mined, smelted or reaction-produced at a custom workshop - it will EXPLOSIVELY BOIL, flooding a small area with delicious syndrome-rich gas. Creatures who inhale the gas will be immediately hit with the syndrome you thoughtfully attached to the material definition earlier!
There are a number of other tokens you can use to control the colour and naming conventions of your syndrome material, referred to as material definition tokens.
It is fully possible to make a nasty disease capable of spreading itself from an infected dwarf to others, though it requires some skill in modding interactions as well. Here is an example of a plague-inflicting interaction:
[INTERACTION:PLAGUE] [I_TARGET:A:CREATURE] [IT_LOCATION:CONTEXT_CREATURE] [IT_FORBIDDEN:NOT_LIVING] [IT_AFFECTED_CLASS:GENERAL_POISON] [IT_MANUAL_INPUT:creatures] [I_EFFECT:ADD_SYNDROME] [IE_TARGET:A] [IE_IMMEDIATE] [SYNDROME] [SYN_NAME:the plague] [SYN_AFFECTED_CLASS:GENERAL_POISON] [CE_FEVER:SEV:250:PROB:100:START:250:PEAK:1500:END:25000] [CE_BLISTERS:SEV:325:PROB:100:BP:BY_CATEGORY:ALL:SKIN:START:250:PEAK:1500:END:25000] [CE_NECROSIS:SEV:300:PROB:100:BP:BY_CATEGORY:ALL:ALL:VASCULAR_ONLY:START:22500:PEAK:23750:END:25000] [CE_CAN_DO_INTERACTION:START:1500:END:25000] [CDI:ADV_NAME:Spread the plague] [CDI:INTERACTION:PLAGUE] [CDI:TARGET:A:LINE_OF_SIGHT] [CDI:TARGET_RANGE:A:10] [CDI:WAIT_PERIOD:30]
As you can see, the syndrome here inflicts blisters, fever and, after roughly a month, necrosis of the whole body - that's when the infected creatures will start dying out. But before that happens, CE_CAN_DO_INTERACTION makes them capable of spreading the plague further.
You also need a disease vector that will bring the plague straight to your fort. (hint: use various species of rats - they're perfect for that). The following code, added to a creature's raws, ensures the creature will infect anybody it encounters:
[CAN_DO_INTERACTION:PLAGUE] [CDI:ADV_NAME:Spread the plague] [CDI:TARGET:A:LINE_OF_SIGHT] [CDI:TARGET_RANGE:A:10] [CDI:WAIT_PERIOD:30]
As soon as the said creature is startled by your dwarves, the fun will begin.
As of version 0.47.01, it may be possible to use a creature's established methods of attack for use in disease-spreading.
Let's use the borrowed example of the plague above. This time, the plague will spread through biting, using the following syndrome code:
[INTERACTION:PLAGUE] [I_TARGET:A:CREATURE] [IT_LOCATION:CONTEXT_CREATURE] [IT_FORBIDDEN:NOT_LIVING] [IT_AFFECTED_CLASS:GENERAL_POISON] [IT_MANUAL_INPUT:creatures] [I_EFFECT:ADD_SYNDROME] [IE_TARGET:A] [IE_IMMEDIATE] [SYNDROME] [SYN_NAME:the plague] [SYN_AFFECTED_CLASS:GENERAL_POISON] [CE_FEVER:SEV:250:PROB:100:START:250:PEAK:1500:END:25000] [CE_BLISTERS:SEV:325:PROB:100:BP:BY_CATEGORY:ALL:SKIN:START:250:PEAK:1500:END:25000] [CE_NECROSIS:SEV:300:PROB:100:BP:BY_CATEGORY:ALL:ALL:VASCULAR_ONLY:START:22500:PEAK:23750:END:25000] [CE_SPECIAL_ATTACK_INTERACTION:INTERACTION:PLAGUE:BP:BY_CATEGORY:TOOTH:START:0:ABRUPT]
The line [CE_SPECIAL_ATTACK_INTERACTION:INTERACTION:BITE_PLAGUE:BP:BY_CATEGORY:MOUTH:BP:BY_CATEGORY:TOOTH:START:0:ABRUPT] allows any infected creature with an attack using mouth or tooth category body parts to immediately spread the disease using said attack. The victim of the attack may then spread the disease if they are able to attack with the needed body part/parts.