Every breath weapon does 1/3 of the monster's current hit points,
except lightning, which does 1/4.

Acid damage is then halved if you have any armor to corrode, or
divided by 4 if you have resist acid and some armor.

Cold or fire damage is divided by 3 if you have permanent resistance
(from a ring, armor, or weapon) or temporary resistance (from a potion
or priest spell), and by 9 if you have both.

Lightning damage is divided by 3 if you have resistance.

Gas damage always has full effect.


Ancient Multi-Hued Dragon:  (40/276)
      2080 total hit points
      lightning:  520/173
      acid:       693/347/173
      fire/cold:  693/231/77
      gas:        693

Even a 40th level half-troll warrior with 18/100 constitution,
heroism, and superheroism would probably not have 693 hit points.
Thus you must never fight AMHD's if you are giving them any
opportunity to breathe on you.  I don't like to go down to level 40
unless I have 231 hit points and resistance, so that I can survive 4
out of 5 breaths from off-screen AMHD's.

Ancient Green Dragon:  (39/269)
      720 total hit points
      gas:        240

Ancient White Dragon:  (38/263)
      704 total hit points
      cold:       235/78/26

Ancient Blue Dragon:  (39/268)
      696 total hit points
      lightning:  174/58

Ancient Black Dragon:  (39/270)
      720 total hit points
      acid:       240/120/60

Ancient Red Dragon:  (40/273)
      840 total hit points
      fire:       280/93/31

Balrog:
      3000 total hit points
      fire:       1000/333/111

Thus a mage with less than 333 hp can be killed by one breath from the
Balrog, before he gets a chance to drink invulnerability potions.  For
a mage to get 333 hp, he must be human, and he must use the grape
jelly trick.


Mature Multi-Hued Dragon:  (38/262)
      640 total hit points
      lightning:  160/53
      acid:       213/107/53
      fire/cold:  213/71/24
      gas:        213

Mature Green Dragon:  (36/256)
      384 total hit points
      gas:        128

Mature White Dragon:  (35/250)
      384 total hit points
      cold:       128/43/14

Mature Blue Dragon:  (36/255)
      384 total hit points
      lightning:  96/32

Mature Black Dragon:  (37/261)
      464 total hit points
      acid:       155/77/39

Mature Red Dragon:  (37/260)
      480 total hit points
      fire:       160/53/18

Young Multi-Hued Dragon:  (36/254)
      320 total hit points
      lightning:  80/27
      acid:       107/53/27
      fire/cold:  107/36/12
      gas:        107