Black Crusade Diseases

Rules for Disease Crafting

The intent for these rules is to allow players and GM's to create new diseases beyond the limited ones in the various books. They are just the basic mechanics and should be suitable altered to suit what they are used for.

Let's Get Infected!
Make your own Nurgle's Blessing! Roll Trade (Chymistry) and Medicae (combination of both) for a crafting test after choosing modifiers.
The total of chosen modifiers cannot exceed -60 or +60.
The GM may assign modifiers for existing samples, equipment or other factors.

DISEASE ATTRIBUTES (choose one or several)
The toughness test to resist disease effects is challenging (+0).
For each additional -10, resisting specific effects may be made more difficult by -10.

  • Fever-inducing: Test toughness daily or suffer fatigue equal to failure levels (-10)
  • Haemorrhaging: Test toughness daily or suffer Blood Loss (-20)
  • Collapsing: Test toughness daily or die (-40)
  • Wasting: Test toughness daily or suffer d5 [roll d5 to determine stat: STR, AGI, TG, INT, WP] ability damage (-10)
  • Deteriorating: Test toughness daily or suffer d5 [roll d4 to determine stat: STR, AGI, INT, WP] permanent ability damage (-30)


  • Major Parasite - Permanent (-60)
  • Minor Parasite - 2x1d10 months (-40)
  • Major Viral - Temporary 2x1d10 weeks (-30)
  • Minor Viral - Temporary 5d10 days (-10)
  • Major Bacterial - Temporary d10 days (+0)
  • Minor Bacterial - Temporary d10/2 days (+20)

For each -10 or +10, victims gain the modifier to their toughness tests to resist an infection.
The baseline modifier to resist infection is +0.

For each +10 or -10, producing a cure and/or vaccination becomes equally more or less challenging. The baseline modifier and time to produce a vaccine is equal to the difficulty to produce the disease sample.


  • Poison (ingestion or injection only) +20
  • Fluid exchange +10
  • Touch -10
  • Airborne -30


  • Fast (day approx.): +0
  • Medium (week approx.) -10
  • Slow (month approx.) -20

Conduct a RITUAL with +0 modifier; gain +10 for each success level for disease crafting test.
Ritualists must resist infection from one of Papa's blessings after successful ritual.
Failure indicates Contempt of the Warp.

Crafting and time benchmarks
Crafting roll: Success and Failure modifies the time needed to produce a sample, one step per level.

  • +60 6d10 minutes
  • +50 d5 hours
  • +40 d10 hours
  • +30 2d10 hours
  • +20 day
  • +10 d5 days
  • +0 d10 days
  • -10 d5 weeks
  • -20 2d5 weeks
  • -30 d5 months
  • -40 2d5 months
  • -50 - year
  • -60 - d5 years

Quantity: Adjust modifier for one step to produce more samples as per the acquisition rules. Benchmark presumes only one sample produced.

Example Disease: Iocanthian Groin-Rot
The Groin-Rot transmits only by exchange of fluids (+10). The first symptoms begin only after a month or so, making it hard to detect and easy to spread by accident (-20). The effects of the parasite are painfully permanent (-60), making the victim suffer d5 Strength ability damage daily if a Toughness test is failed (-10) and a high fever if another Toughness test is failed (-10). Luckily, the infection can usually be resisted by fit individuals (+20 to resistance) and the Iocanthian shamans have found many herbs to treat the parasite (+10 to antidote).
TOTAL MODIFIER TO CRAFT: -60 Medicae test and d5 months of work to produce one working sample.

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