Armor class - Revision history

EasterlyIrk: clarify ac/dr rules for dnh

2026-03-20T21:21:33Z

clarify ac/dr rules for dnh

Umbire the Phantom: /* dNetHack */ copyedit

2026-03-20T13:52:41Z

‎dNetHack: copyedit

Ais523: /* Armor class and damage averages */ {{todo}} – this section needs fixing but I don't have time to do it right now

2026-01-15T19:04:06Z

‎Armor class and damage averages: {{todo}} – this section needs fixing but I don't have time to do it right now

Ais523: /* Damage reduction */ explain the recently fixed (and thus unfixed in 3.6) bug here too, as it's the other article that's relevant to it

2026-01-15T19:00:32Z

‎Damage reduction: explain the recently fixed (and thus unfixed in 3.6) bug here too, as it's the other article that's relevant to it

Scyrmion: /* Armor class and accuracy */ Negative AC randomization applies to melee and not missile attacks.

2025-12-27T16:33:55Z

‎Armor class and accuracy: Negative AC randomization applies to melee and not missile attacks.

Umbire the Phantom: /* SLASH'EM */ wordsmithing

2024-08-07T19:37:56Z

‎SLASH'EM: wordsmithing

Umbire the Phantom: /* Strategy */ word choice

2024-08-07T19:34:40Z

‎Strategy: word choice

Umbire the Phantom: /* SporkHack */ detail

2024-04-11T06:41:32Z

‎SporkHack: detail

Umbire the Phantom: /* Variants */ spork

2024-04-11T01:21:42Z

‎Variants: spork

Umbire the Phantom: pothole

2023-11-10T07:31:17Z

pothole

@@ Line 498: / Line 498: @@
 ===dNetHack===
-In [[dNetHack]], AC and damage reduction are applied and calculated separately, as well as differently&mdash;each piece of armor now has an AC value and a '''native damage reduction''' (or '''DR''') value.
+In [[dNetHack]], AC and damage reduction are applied and calculated separately, as well as differently&mdash;each piece of armor now has an AC value and a '''native damage reduction''' (or '''DR''') value. The AC value affects the miss chance, similar to vanilla, but does not reduce damage for attacks that hit. DR is used for reducing the damage of successful hits instead.
-There are three categories for a monster's AC: their natural base AC, their "dodge" AC (which represents the ability to dodge attacks, and is unrelated to the dexterity stat), and any "protection" AC from other forms of defense (such as divine protection or force fields). "Dodge" AC can be nullified by immobilizing the monster in question, e.g., trapping or paralyzing them; "protection" AC can be nullified with [[cancellation]]. Similarly, DR comes in two forms: natural DR represents physical toughness, while DR from "protection" represents divine fortitude or other special forms of resistance as with AC (which can similarly be nullified by cancellation).
+There are four categories for AC:
-Most attacks roll against total AC and DR from all applicable sources, while [[touch]] attacks exclude AC and DR from physical armor&mdash;AC and DR from physically-worn armor are generally considered to be their own category, and monsters can have DR values of both types for one or more multiple body part slots: the feet or legs, the lower torso, the upper torso, the hands or arms, and the head. AC values for worn armor determine whether or not an attack will be blocked by that armor, while native damage reduction or DR is applied on a per-slot basis for each individual attack, with each piece of armor applying its DR value to attacks targeting one or more parts of the defender's body. For DR values of more than 10, damage done by a given attack targeting a certain slot is reduced by <math>10 + d(DR - 10)</math>, e.g. attacks against a slot with 18 DR effectively have their damage reduced by 10 + d8 (or 11-18) on each hit.
+Your total AC is the sum of all 4 categories. However, some effects will ignore specific categories of AC. For example, [[touch]] attacks or phasing weapons will ignore armor AC, being paralyzed or otherwise immobilized will temporarily nullify dodge AC, and cancellation can zero out certain sources of divine AC. AC and attack roll calculations work very similarly to vanilla, though dNetHack adds more modifiers to the formula. In particular, various intelligent monsters know how to use weapons with varying skill, so they will get an additional skill-based accuracy bonus just like players do.
 ===notdNetHack===

@@ Line 498: / Line 498: @@
 ===dNetHack===
-In [[dNetHack]], AC and damage reduction (or '''DR''') are applied and calculated separately, as well as differently - each piece of armor now has an AC value and a DR value.
+In [[dNetHack]], AC and damage reduction are applied and calculated separately, as well as differently&mdash;each piece of armor now has an AC value and a '''native damage reduction''' (or '''DR''') value.
-AC values determine whether or not the attack is blocked by your armor/protection; DR is applied on a per-slot basis for each individual attack, with each piece of armor applying its DR value to attacks targeting one or more slots: feet/legs, lower torso, upper torso, hands, and head. A slot that a target monster does not possess is ignored. For DR values of more than 10, damage done by a given attack targeting a certain slot is reduced by <math>10 + d(DR - 10)</math>, e.g. attacks against a slot with 18 DR effectively have their damage reduced by 10 + d8 (or 11-18) on each hit
+There are three categories for a monster's AC: their natural base AC, their "dodge" AC (which represents the ability to dodge attacks, and is unrelated to the dexterity stat), and any "protection" AC from other forms of defense (such as divine protection or force fields). "Dodge" AC can be nullified by immobilizing the monster in question, e.g., trapping or paralyzing them; "protection" AC can be nullified with [[cancellation]]. Similarly, DR comes in two forms: natural DR represents physical toughness, while DR from "protection" represents divine fortitude or other special forms of resistance as with AC (which can similarly be nullified by cancellation).
-There are three categories for a monster's AC: their natural base AC, their "dodge" AC (which represents the ability to dodge attacks, and is unrelated to the dexterity stat), and any "protection" AC from other forms of defense (such as divine protection or force fields). "Dodge" AC can be nullified by immobilizing the monster in question, e.g., trapping or paralyzing them; "protection" AC can be nullified with [[cancellation]]. Similarly, DR comes in two forms: natural DR which represents physical toughness, and DR from "protection" as with AC (which can similarly be nullified by cancellation). AC and DR from physically-worn armor are generally considered to be its own category; most attacks roll against total AC and DR from all applicable sources, while [[touch]] attacks exclude AC and DR from physical armor.
+Most attacks roll against total AC and DR from all applicable sources, while [[touch]] attacks exclude AC and DR from physical armor&mdash;AC and DR from physically-worn armor are generally considered to be their own category, and monsters can have DR values of both types for one or more multiple body part slots: the feet or legs, the lower torso, the upper torso, the hands or arms, and the head. AC values for worn armor determine whether or not an attack will be blocked by that armor, while native damage reduction or DR is applied on a per-slot basis for each individual attack, with each piece of armor applying its DR value to attacks targeting one or more parts of the defender's body. For DR values of more than 10, damage done by a given attack targeting a certain slot is reduced by <math>10 + d(DR - 10)</math>, e.g. attacks against a slot with 18 DR effectively have their damage reduced by 10 + d8 (or 11-18) on each hit.
 ===notdNetHack===

← Older revision		Revision as of 19:04, 15 January 2026
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	===Armor class and damage averages===		===Armor class and damage averages===
		+
		+	{{todo\|The air elemental damage here is wrong, because AC doesn't reduce air elemental damage while engulfed.}}
		+
	The following table shows the mean damage some monsters can inflict at various armor classes, with poison damage being ignored. The damage is calculated "per turn" of a normal speed player (12), so the chart shows the cumulative damage of 1.8 bites from a giant bat, or 3 pummels from an air elemental. The air elemental damage assumes a 100% hit rate (i.e., that the elemental has already engulfed the player).		The following table shows the mean damage some monsters can inflict at various armor classes, with poison damage being ignored. The damage is calculated "per turn" of a normal speed player (12), so the chart shows the cumulative damage of 1.8 bites from a giant bat, or 3 pummels from an air elemental. The air elemental damage assumes a 100% hit rate (i.e., that the elemental has already engulfed the player).

← Older revision		Revision as of 19:00, 15 January 2026
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	In this example, the monster hits and deals 5 points of base damage. The damage is then reduced by a random number between 1 and the absolute value of your AC, which in this case would be any value from 1 to 20. If this produces a value lower than 1, it is set to 1 so that the monster will always do at least 1 point of damage if it hits. If you have [[half physical damage]], the property is applied after this reduction.		In this example, the monster hits and deals 5 points of base damage. The damage is then reduced by a random number between 1 and the absolute value of your AC, which in this case would be any value from 1 to 20. If this produces a value lower than 1, it is set to 1 so that the monster will always do at least 1 point of damage if it hits. If you have [[half physical damage]], the property is applied after this reduction.
		+
		+	Due to a long-standing bug, damage reduction from AC is not applied while [[engulfed]].

	==Strategy==		==Strategy==

@@ Line 15: / Line 15: @@
 </math>
-If your AC is less than 0, the formula for the target number is instead:
+If your AC is less than 0, and you are being attacked by melee, the formula for the target number is instead:
 <math>

@@ Line 487: / Line 487: @@
 |}
-[[Doppelganger (starting race)|Doppelgangers]] and [[Monk]]s have complicated special bonuses: Doppelgangers get the bonus for not wearing any armor, and Monks get the bonus for not wearing a shield, not wielding a weapon, and not wearing body armor other than cloaks and robes.
+[[Doppelganger (starting race)|Doppelgangers]] and [[Monk]]s have additional conditions for their dexterity bonuses: Doppelgangers get the bonus for not wearing any armor, and Monks get the bonus for not wearing a shield, not wielding a weapon, and not wearing body armor other than cloaks and [[Robe (SLASH'EM)|robes]].
 ===SporkHack===

@@ Line 49: / Line 49: @@
 Improving your armor class is the first priority for almost any starting character, from a [[Knight]] or [[Samurai]] looking for something lighter and just as protective as their initial body armor, to an [[Archeologist]] or [[Tourist]] trying to find anything to replace their meager [[leather jacket]] or cover their [[Hawaiian shirt]]. However, armor class is only one portion of a player (or player character's) kit, and a good AC alone is not enough to protect from some attacks with additional effects, particularly elemental ones - in addition to improving your AC, you will also need to obtain [[resistance]]s and other properties such as [[reflection]] to increase your odds of survival. Even -50 AC will eventually fail if you have no other protection against [[poison]]ous stings or even a [[wand of death]].
-An armor class of 0 is often a decent beginning goal, though this does not guarantee safety against some deadly early monsters such as [[jaguar]]s, [[unicorn]]s and [[soldier ants]] (all with a [[monster difficulty]] of 6). While you will eventually want to push towards -10 AC for taking on most early and mid-game monsters such as these, you will also want to refine and adapt your tactics accordingly - one of the best defenses is usually a good offense. Keep in mind as well that slower monsters can be just as threatening as fast ones, if not more so: [[Dwarf (monster)|dwarves]] wielding [[Dwarvish mattock|mattocks]], [[mimic]]s and [[mumakil]] can deal considerable melee damage, making it vital to leverage your better speed against them.
+An armor class of 0 is often a decent beginning goal, though this does not guarantee safety against some deadly early monsters such as [[jaguar]]s, [[unicorn]]s and [[soldier ants]] (all with a [[monster difficulty]] of 6). While you will eventually want to push towards -10 AC for taking on most early and mid-game monsters such as these, you will also want to refine and adapt your tactics accordingly - one of the best defenses is usually a good offense. Keep in mind as well that slower monsters can be just as threatening as fast ones, if not more so: [[mimic]]s, [[mumakil]] and some monsters that can wield strong weapons (e.g. [[Dwarf (monster)|dwarves]] wielding [[Dwarvish mattock|mattocks]]) can deal considerable melee damage, making it vital to leverage your better speed against them.
 ===Armor class and ascension===

@@ Line 490: / Line 490: @@
 ===SporkHack===
-In [[SporkHack]], monsters gain an AC bonus dependent on their [[monster level]], making higher-level foes generally much harder to hit and deal damage to.
+In [[SporkHack]], monsters gain a bonus to their base AC dependent on their [[monster level]]: higher-level foes are generally much harder to hit and deal damage to, while higher-level pets have better odds of survival.
 ===dNetHack===

← Older revision		Revision as of 01:21, 11 April 2024
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	[[Doppelganger (starting race)\|Doppelgangers]] and [[Monk]]s have complicated special bonuses: Doppelgangers get the bonus for not wearing any armor, and Monks get the bonus for not wearing a shield, not wielding a weapon, and not wearing body armor other than cloaks and robes.		[[Doppelganger (starting race)\|Doppelgangers]] and [[Monk]]s have complicated special bonuses: Doppelgangers get the bonus for not wearing any armor, and Monks get the bonus for not wearing a shield, not wielding a weapon, and not wearing body armor other than cloaks and robes.
		+
		+	===SporkHack===
		+	In [[SporkHack]], monsters gain an AC bonus dependent on their [[monster level]], making higher-level foes generally much harder to hit and deal damage to.

	===dNetHack===		===dNetHack===