System	
  Reference	
   Document	
  5.1 	
   199	
  
Diseases 
A	
  plague	
  ravages	
  the	
  kingdom,	
  setting	
  the	
  
adventurers	
  on	
  a	
  quest	
  to	
  find	
  a	
  cure.	
  An	
  adventurer	
  
emerges	
  from	
  an	
  ancient	
  tomb,	
  unopened	
  for 	
  
centuries,	
  and	
  soon	
  finds	
  herself	
  suffering	
  from	
  a	
  
wasting	
  illness.	
  A	
  warlock	
  offends	
  some	
  dark	
  power	
  
and	
  contracts	
  a	
  strange	
  affliction	
  that	
  spreads	
  
whenever	
  he	
  casts	
  spells. 	
  
	
   A	
  simple	
  outbreak	
  might	
  amount	
  to	
  little	
  more	
  
than	
  a	
  small	
  drain	
  on	
  party	
  reso urces,	
  curable	
  by	
  a	
  
casting	
  of	
  lesser	
  restoration .	
  A	
  more	
  complicated	
  
outbreak	
  can	
  form	
  the	
  basis	
  of	
  one	
  or	
  more	
  
adventures	
  as	
  characters	
  search	
  for	
  a	
  cure,	
  stop	
  the	
  
spread	
  of	
  the	
  disease,	
  and	
  deal	
  with	
  the	
  
consequences.	
  
	
   A	
  disease	
  that	
  does	
  more	
  than	
  infe ct	
  a	
  few	
  party	
  
members	
  is	
  primarily	
  a	
  plot	
  device.	
  The	
  rules	
  help	
  
describe	
  the	
  effects	
  of	
  the	
  disease	
  and	
  how	
  it	
  can	
  be	
  
cured,	
  but	
  the	
  specifics	
  of	
  how	
  a	
  disease	
  works	
  
aren’t	
  bound	
  by	
  a	
  common	
  set	
  of	
  rules.	
  Diseases	
  can	
  
affect	
  any	
  creature,	
  and	
  a	
  given	
  ill ness	
  might	
  or	
  
might	
  not	
  pass	
  from	
  one	
  race	
  or	
  kind	
  of	
  creature	
  to	
  
another.	
  A	
  plague	
  might	
  affect	
  only	
  constructs	
  or	
  
undead,	
  or	
  sweep	
  through	
  a	
  halfling	
  neighborhood	
  
but	
  leave	
  other	
  races	
  untouched.	
  What	
  matters	
  is	
  the	
  
story	
  you	
  want	
  to	
  tell. 	
  
Sample Diseases 
The	
  diseases	
  here	
  illustrate	
  the	
  variety	
  of	
  ways	
  
disease	
  can	
  work	
  in	
  the	
  game.	
  Feel	
  free	
  to	
  alter	
  the	
  
saving	
  throw	
  DCs,	
  incubation	
  times,	
  symptoms,	
  and	
  
other	
  characteristics	
  of	
  these	
  diseases	
  to	
  suit	
  your	
  
campaign.	
  
Cackle Fever 
This	
  disease	
  targets	
  human oids,	
  although	
  gnomes	
  
are	
  strangely	
  immune.	
  While	
  in	
  the	
  grips	
  of	
  this	
  
disease,	
  victims	
  frequently	
  succumb	
  to	
  fits	
  of	
  mad	
  
laughter,	
  giving	
  the	
  disease	
  its	
  common	
  name	
  and	
  its	
  
morbid	
  nickname:	
  “the	
  shrieks.” 	
  
	
   Symptoms	
  manifest	
  1d4	
  hours	
  after	
  infection	
  and	
  
include	
  fever	
  and	
  disorientation.	
  The	
  infected	
  
creature	
  gains	
  one	
  level	
  of	
  exhaustion	
  that	
  can’t	
  be	
  
removed	
  until	
  the	
  disease	
  is	
  cured. 	
  
	
   Any	
  event	
  that	
  causes	
  the	
  infected	
  creature	
  great	
  
stress—including	
  entering	
  combat,	
  taking	
  damage,	
  
experiencing	
  fear,	
  o r	
  having	
  a	
  nightmare —forces	
  the	
  
creature	
  to	
  make	
  a	
  DC	
  13	
  Constitution	
  saving	
  throw.	
  
On	
  a	
  failed	
  save,	
  the	
  creature	
  takes	
  5	
  (1d10)	
  psychic	
  
damage	
  and	
  becomes	
  incapacitated	
  with	
  mad	
  
laughter	
  for	
  1	
  minute.	
  The	
  creature	
  can	
  repeat	
  the	
  
saving	
  throw	
  at	
  the	
  end	
  of	
  each	
  of	
  its	
  turns,	
  ending	
  
the	
  mad	
  laughter	
  and	
  the	
  incapacitated	
  condition	
  on	
  
a	
  success.	
  
	
   Any	
  humanoid	
  creature	
  that	
  starts	
  its	
  turn	
  within	
  
10	
  feet	
  of	
  an	
  infected	
  creature	
  in	
  the	
  throes	
  of	
  mad	
  
laughter	
  must	
  succeed	
  on	
  a	
  DC	
  10	
  Constitution	
  
saving	
  throw	
  or 	
  also	
  become	
  infected	
  with	
  the	
  
disease.	
  Once	
  a	
  creature	
  succeeds	
  on	
  this	
  save,	
  it	
  is	
  
immune	
  to	
  the	
  mad	
  laughter	
  of	
  that	
  particular	
  
infected	
  creature	
  for	
  24	
  hours. 	
  
	
   At	
  the	
  end	
  of	
  each	
  long	
  rest,	
  an	
  infected	
  creature	
  
can	
  make	
  a	
  DC	
  13	
  Constitution	
  saving	
  thro w.	
  On	
  a	
  
successful	
  save,	
  the	
  DC	
  for	
  this	
  save	
  and	
  for	
  the	
  save	
  
to	
  avoid	
  an	
  attack	
  of	
  mad	
  laughter	
  drops	
  by	
  1d6.	
  
When	
  the	
  saving	
  throw	
  DC	
  drops	
  to	
  0,	
  the	
  creature	
  
recovers	
  from	
  the	
  disease.	
  A	
  creature	
  that	
  fails	
  three	
  
of	
  these	
  saving	
  throws	
  gains	
  a	
  randomly 	
  determined	
  
form	
  of	
  indefinite	
  madness,	
  as	
  described	
  later. 	
  
Sewer Plague 
Sewer	
  plague	
  is	
  a	
  generic	
  term	
  for	
  a	
  broad	
  category	
  
of	
  illnesses	
  that	
  incubate	
  in	
  sewers,	
  refuse	
  heaps,	
  
and	
  stagnant	
  swamps,	
  and	
  which	
  are	
  sometimes	
  
transmitted	
  by	
  creatures	
  that	
  dwel l	
  in	
  those	
  areas,	
  
such	
  as	
  rats	
  and	
  otyughs. 	
  
When	
  a	
  humanoid	
  creature	
  is	
  bitten	
  by	
  a	
  creature	
  
that	
  carries	
  the	
  disease,	
  or	
  when	
  it	
  comes	
  into	
  
contact	
  with	
  filth	
  or	
  offal	
  contaminated	
  by	
  the	
  
disease,	
  the	
  creature	
  must	
  succeed	
  on	
  a	
  DC	
  11	
  
Constitution	
  saving	
   throw	
  or	
  become	
  infected. 	
  
	
   It	
  takes	
  1d4	
  days	
  for	
  sewer	
  plague’s	
  symptoms	
  to	
  
manifest	
  in	
  an	
  infected	
  creature.	
  Symptoms	
  include	
  
fatigue	
  and	
  cramps.	
  The	
  infected	
  creature	
  suffers	
  
one	
  level	
  of	
  exhaustion,	
  and	
  it	
  regains	
  only	
  half	
  the	
  
normal	
  number	
  of	
  hit	
  poin ts	
  from	
  spending	
  Hit	
  Dice	
  
and	
  no	
  hit	
  points	
  from	
  finishing	
  a	
  long	
  rest. 	
  
	
   At	
  the	
  end	
  of	
  each	
  long	
  rest,	
  an	
  infected	
  creature	
  
must	
  make	
  a	
  DC	
  11	
  Constitution	
  saving	
  throw.	
  On	
  a	
  
failed	
  save,	
  the	
  character	
  gains	
  one	
  level	
  of	
  
exhaustion.	
  On	
  a	
  successful	
  save,	
  th e	
  character’s	
  
exhaustion	
  level	
  decreases	
  by	
  one	
  level.	
  If	
  a	
  
successful	
  saving	
  throw	
  reduces	
  the	
  infected	
  
creature’s	
  level	
  of	
  exhaustion	
  below	
  1,	
  the	
  creature	
  
recovers	
  from	
  the	
  disease. 	
  
Sight Rot 
This	
  painful	
  infection	
  causes	
  bleeding	
  from	
  the	
  eyes	
  
and	
  eventually	
  blinds	
  the	
  victim. 	
  
	
   A	
  beast	
  or	
  humanoid	
  that	
  drinks	
  water	
  tainted	
  by	
  
sight	
  rot	
  must	
  succeed	
  on	
  a	
  DC	
  15	
  Constitution	
  
saving	
  throw	
  or	
  become	
  infected.	
  One	
  day	
  after	
  
infection,	
  the	
  creature’s	
  vision	
  starts	
  to	
  become	
  
blurry.	
  The	
  creature	
  takes	
  a	
  −1	
  pena lty	
  to	
  attack	
  
rolls	
  and	
  ability	
  checks	
  that	
  rely	
  on	
  sight.	
  At	
  the	
  end	
  