System	
  Reference	
   Document	
  5.1 	
   86	
  
The Environment 
By	
  its	
  nature,	
  adventuring	
  involves	
  delving	
  into	
  
places	
  that	
  are	
  dark,	
  dangerous,	
  and	
  full	
  of	
  mysteries	
  
to	
  be	
  explored.	
  The	
  rules	
  in	
  this	
  section	
  cover	
  some	
  
of	
  the	
  most	
  important	
  ways	
  in	
  which	
   adventurers	
  
interact	
  with	
  the	
  environment	
  in	
  such	
  places. 	
  
Falling 
A	
  fall	
  from	
  a	
  great	
  height	
  is	
  one	
  of	
  the	
  most	
  common	
  
hazards	
  facing	
  an	
  adventurer.	
  At	
  the	
  end	
  of	
  a	
  fall,	
  a	
  
creature	
  takes	
  1d6	
  bludgeoning	
  damage	
  for	
  every	
  10	
  
feet	
  it	
  fell,	
  to	
  a	
  maximum	
  of	
  20 d6.	
  The	
  creature	
  lands	
  
prone,	
  unless	
  it	
  avoids	
  taking	
  damage	
  from	
  the	
  fall. 	
  
Suffocating 
A	
  creature	
  can	
  hold	
  its	
  breath	
  for	
  a	
  number	
  of	
  
minutes	
  equal	
  to	
  1	
  +	
  its	
  Constitution	
  modifier	
  
(minimum	
  of	
  30	
  seconds). 	
  
	
   When	
  a	
  creature	
  runs	
  out	
  of	
  breath	
  or	
  is	
   choking,	
  
it	
  can	
  survive	
  for	
  a	
  number	
  of	
  rounds	
  equal	
  to	
  its	
  
Constitution	
  modifier	
  (minimum	
  of	
  1	
  round).	
  At	
  the	
  
start	
  of	
  its	
  next	
  turn,	
  it	
  drops	
  to	
  0	
  hit	
  points	
  and	
  is	
  
dying,	
  and	
  it	
  can’t	
  regain	
  hit	
  points	
  or	
  be	
  stabilized	
  
until	
  it	
  can	
  breathe	
  again. 	
  
	
   For	
  example,	
  a	
  creature	
  with	
  a	
  Constitution	
  of	
  14	
  
can	
  hold	
  its	
  breath	
  for	
  3	
  minutes.	
  If	
  it	
  starts	
  
suffocating,	
  it	
  has	
  2	
  rounds	
  to	
  reach	
  air	
  before	
  it	
  
drops	
  to	
  0	
  hit	
  points. 	
  
Vision and Light 
The	
  most	
  fundamental	
  tasks	
  of	
  adventuring—
noticing	
  danger,	
  finding	
  hidd en	
  objects,	
  hitting	
  an	
  
enemy	
  in	
  combat,	
  and	
  targeting	
  a	
  spell,	
  to	
  name	
  just	
  
a	
  few—rely	
  heavily	
  on	
  a	
  character’s	
  ability	
  to	
  see.	
  
Darkness	
  and	
  other	
  effects	
  that	
  obscure	
  vision	
  can	
  
prove	
  a	
  significant	
  hindrance. 	
  
	
   A	
  given	
  area	
  might	
  be	
  lightly	
  or	
  heavily	
  obsc ured.	
  
In	
  a	
  lightly	
  obscured 	
  area,	
  such	
  as	
  dim	
  light,	
  patchy	
  
fog,	
  or	
  moderate	
  foliage,	
  creatures	
  have	
  
disadvantage	
  on	
  Wisdom	
  (Perception)	
  checks	
  that	
  
rely	
  on	
  sight.	
  
	
   A	
  heavily	
  obscured	
   area—such	
  as	
  darkness,	
  
opaque	
  fog,	
  or	
  dense	
  foliage —blocks	
  vision	
  entire ly.	
  
A	
  creature	
  effectively	
  suffers	
  from	
  the	
  blinded	
  
condition	
  (see	
  appendix	
   PH-­‐‑A)	
  when	
  trying	
  to	
  see	
  
something	
  in	
  that	
  area. 	
  
	
   The	
  presence	
  or	
  absence	
  of	
  light	
  in	
  an	
  
environment	
  creates	
  three	
  categories	
  of	
  
illumination:	
  bright	
  light,	
  dim	
  light,	
  and	
  darkness .	
  
	
   Bright	
  light	
  lets	
  most	
  creatures	
  see	
  normally.	
  
Even	
  gloomy	
  days	
  provide	
  bright	
  light,	
  as	
  do	
  torches,	
  
lanterns,	
  fires,	
  and	
  other	
  sources	
  of	
  illumination	
  
within	
  a	
  specific	
  radius. 	
  
	
   Dim	
  light,	
  also	
  called	
  shadows,	
  creates	
  a	
  lightly	
  
obscured	
  area.	
  An	
  area	
  o f	
  dim	
  light	
  is	
  usually	
  a	
  
boundary	
  between	
  a	
  source	
  of	
  bright	
  light,	
  such	
  as	
  a	
  
torch,	
  and	
  surrounding	
  darkness.	
  The	
  soft	
  light	
  of	
  
twilight	
  and	
  dawn	
  also	
  counts	
  as	
  dim	
  light.	
  A	
  
particularly	
  brilliant	
  full	
  moon	
  might	
  bathe	
  the	
  land	
  
in	
  dim	
  light.	
  
	
   Darkness	
  creates	
  a	
  heavily	
  obscured	
  area.	
  
Characters	
  face	
  darkness	
  outdoors	
  at	
  night	
  (even	
  
most	
  moonlit	
  nights),	
  within	
  the	
  confines	
  of	
  an	
  unlit	
  
dungeon	
  or	
  a	
  subterranean	
  vault,	
  or	
  in	
  an	
  area	
  of	
  
magical	
  darkness. 	
  
Blindsight 
A	
  creature	
  with	
  blindsight	
  can	
  perceive	
  its	
  
surroundings	
  without	
  relying	
  on	
  sight,	
  within	
  a	
  
specific	
  radius.	
  Creatures	
  without	
  eyes,	
  such	
  as	
  
oozes,	
  and	
  creatures	
  with	
  echolocation	
  or	
  
heightened	
  senses,	
  such	
  as	
  bats	
  and	
  true	
  dragons,	
  
have	
  this	
  sense. 	
  
Darkvision 
Many	
  creatures	
  in	
  fantasy	
  gaming	
  worlds ,	
  especially	
  
those	
  that	
  dwell	
  underground,	
  have	
  darkvision.	
  
Within	
  a	
  specified	
  range,	
  a	
  creature	
  with	
  darkvision	
  
can	
  see	
  in	
  darkness	
  as	
  if	
  the	
  darkness	
  were	
  dim	
  light,	
  
so	
  areas	
  of	
  darkness	
  are	
  only	
  lightly	
  obscured	
  as	
  far	
  
as	
  that	
  creature	
  is	
  concerned.	
  How ever,	
  the	
  creature	
  
can’t	
  discern	
  color	
  in	
  darkness,	
  only	
  shades	
  of	
  gray. 	
  
Truesight 
A	
  creature	
  with	
  truesight	
  can,	
  out	
  to	
  a	
  specific	
  range,	
  
see	
  in	
  normal	
  and	
  magical	
  darkness,	
  see	
  invisible	
  
creatures	
  and	
  objects,	
  automatically	
  detect	
  visual	
  
illusions	
  and	
  su cceed	
  on	
  saving	
  throws	
  against	
  them,	
  
and	
  perceives	
  the	
  original	
  form	
  of	
  a	
  shapechanger	
  or	
  
a	
  creature	
  that	
  is	
  transformed	
  by	
  magic.	
  
Furthermore,	
  the	
  creature	
  can	
  see	
  into	
  the	
  Ethereal	
  
Plane.	
  
Food and Water 
Characters	
  who	
  don’t	
  eat	
  or	
  drink	
  suffer	
  the	
  effect s	
  
of	
  exhaustion	
  (see	
  appendix	
   PH-­‐‑A).	
  Exhaustion	
  
caused	
  by	
  lack	
  of	
  food	
  or	
  water	
  can’t	
  be	
  removed	
  
until	
  the	
  character	
  eats	
  and	
  drinks	
  the	
  full	
  required	
  
amount.	
  
Food 
A	
  character	
  needs	
  one	
  pound	
  of	
  food	
  per	
  day	
  and	
  can	
  
make	
  food	
  last	
  longer	
  by	
  subsisting	
  on	
   half	
  rations.	
  