This page contains various calculations, such as a creature's tohit chance.
Tohit chance: monsters hitting you[]
The percentage chance that a creature will hit you on any given attack is:
HIT% = ( PLAYER AC  10 )  ( MONSTER TOHIT )
HIT% is reduced by 15 if you are invisible.
Many creatures get more than one attack per turn. Each attack will have its own chance of hitting or missing.
Damage amount: monsters hitting you[]
Once a monster has hit you, it does damage:
DAM = ( DAMAGE BASE )  ( ( 10  PLAYER AC ) × ( FACTOR ) )
 FACTOR is a random number between 1.00 and 1.50.
 DAMAGE BASE is a number within the range listed for each creature in the monsters table.
If DAM is calculated to be less than one, it is rounded up to one.
If you have fragile skin, DAM is doubled.
If you are invulnerable, DAM is set to zero.
Tohit chance: you hitting monsters[]
This formula determines the percentage chance that you will hit your opponent:
HIT % = ( PLAYER STRENGTH / 7 )  ( 2 X ( 10  MONSTER'S AC ) ) + ( PLAYER LUCK / 5 ) + ( PLAYER EXPERIENCE LEVEL ) + 50 + ( PLAYER'S WEAPON BONUS X 3 )
The HIT % value is then modified as follows:
Less than two eyes  10 per missing eye 
More than two eyes  +10 per extra eye 
Strength greater than eighteen  + 4 X ( STRENGTH  18 ) 
Decimal strength present
(Example: STR = 18.86) 
+ ( DECIMAL / 25 )
(Example: 86 / 25 = +3 ) 
Weapon modifiers (not listed = + 0): 

Weaponmaster bonus  + 10 
Weaponmaster wielding sai or katana (in addition to +10 above)  + 10 
Phasing penalty   40 
Phasing and wielding phaseblade (in addition to 40 above)  + 65 
Blind penalty (in addition to missing eyes)   5 
Werecreature bonus (when prowling)  + 25 
Wearing crystal gloves, wielding no weapon  + 50 
Victim invisible   5 to  8 
Victim immobilized (asleep etc...)  + 50 
Damage amount: you hitting monsters[]
This formula determines the amount of damage you inflict on your opponent:
DAM = ( PLAYER STRENGTH / 7 ) + ( PLAYER LUCK / 20 ) + ( PLAYER EXPERIENCE LEVEL / 3 ) + ( PLAYER'S WEAPON BONUS ) + ( DAMAGE BASE* )
* DAMAGE BASE is one of a range of numbers indicated in the weapon listings below. If you wield no weapon, your DAMAGE BASE is two to four. Each time you hit an opponent, a number will be chosen randomly from the range of numbers. The damage base distributions follow a bell curve model with varying standard deviations. The DAM value is then modified as follows:
Strength greater than eighteen  + 5 X ( STRENGTH  18 ) 
Decimal strength present
(Example: STR = 18.86) 
+ ( DECIMAL / 20 )
(Example: 86 / 20 = + 4 ) 
Weaponmaster  + 5 
Weaponmaster wielding sai or katana (in addition to +5 above)  + 10 
Wounding victim (as weaponmaster)  + 21 to 35 
Phasing penalty   4 
Phasing and wielding phaseblade (in addition to 4 above)  + 12 
Werecreature bonus (when prowling)  + 15 
Hitting undead with an ivory staff  + 21 to 30 
Hitting a werewolf with a silver sword  Werewolf dies 
Wearing crystal gloves, wielding no weapon  + 40 
DAM will never be less than zero. If it is calculated to be negative, it is set to zero. Some creatures have special defenses that modify the values of HIT % and DAM. Those defenses will be listed individually with those creatures.
Distance: you shooting monsters[]
This formula determines how far you can throw an item:
DIST = the greater of ( STRENGTH  9  ( WEIGHT / 7 ) ) or 3
(The weights of items are not listed... yet.)
DIST is then modified by the following:
Weapon thrown is Mjollnir  + 4 
Weapon is an arrow fired from a bow  + 5 
Weapon is a bolt fired from a crossbow  + 5 
Tohit chance: you shooting monsters[]
This formula determines the percentage chance that you will hit your opponent with a thrown or fired item:
HIT % = ( PLAYER STRENGTH / 7 )  ( 2 X ( 10  MONSTER'S AC ) ) + ( PLAYER LUCK / 10 ) + 30 + ( PLAYER'S WEAPON TO HIT ) + ( PLAYER'S WEAPON SKILL* / 10 )
* The skill with weapon is assumed to be zero unless otherwise specified in abilities on the diagnostic screen. The HIT % value is then modified as follows:
Less than two eyes  10 per missing eye 
Greater than two eyes  +10 per extra eye 
Strength greater than eighteen  + 4 X ( STRENGTH  18 ) 
Decimal strength present
(Example: STR = 18.86) 
+ ( DECIMAL / 25 )
Example: 86 / 25 = +3 
Weapon modifiers (not listed = + 0): 

Weaponmaster bonus  + 10 
Phasing penalty   40 
Blind penalty (in addition to missing eyes)   5 
Werecreature bonus (when prowling)  + 25 
Victim invisible   5 to  8 
Victim immobilized (asleep etc...)  + 50 
Damage amount: you shooting monsters[]
This formula determines the amount of damage you inflict on your opponent:
DAM = ( PLAYER STRENGTH / 14 ) + ( PLAYER LUCK / 40 ) + ( PLAYER EXPERIENCE LEVEL / 6 ) + ( PLAYER'S WEAPON BONUS ) + ( THROWN DAMAGE BASE* )
* THROWN DAMAGE BASE is one of a range of numbers indicated in the weapon listings below. Each time a player hits an opponent, a number will be chosen randomly from the range of numbers. The damage base distributions follow a bell curve model with varying standard deviations. The DAM value is then modified as follows:
Strength greater than eighteen  + 2.5 X ( STRENGTH  18 ) 
Decimal strength present
(Example: STR = 18.86) 
+ ( DECIMAL / 40 )
(Example: 86 / 40 = + 2 ) 
Weaponmaster  + 2.5 
Phasing penalty   2 
Wielding appropriate bow for projectile  + BOW BONUS 
DAM will never be less than zero. If it is calculated to be negative, it is truncated to zero. If DAM is fractional, the remainder will be truncated.