Resistances and Immunities
From Basin Wiki
Contents |
Basics
Monsters can have % resistance to various types of damage: physical, magic, elemental (fire, lightning and cold) and poison. % Resistance reduces displayed damage by a percentage, so 25% resistance results in 75% (100% - 25%) displayed damage i.e. every 100 points of damage will be reduced to 75. When a monster has 100+% resistance, it becomes immune to that damage type (0% displayed damage).
Inherent Resistances and Immunities
A monster's inherent resistances and immunities are always applied first, and without restriction, by values in MonStats.txt. In theory, a monster can have inherent immunities to all six damage types, although in practice only one (the Pit Lords of the Pandemonium Event) has more than two.
Acquired Resistances and Immunities
There are modifiers that apply % resistance bonuses which, when added to a monster's inherent values, can result in acquired resistances and immunities. If a monster already has two (or more) inherent immunities, it can acquire no more from modifiers; if it has less than two inherent immunities, then it is restricted to a maximum of two. Once two inherent and/or acquired immunities have been applied, any % resistance bonuses that would result in further immunities or boost the existing ones are not applied.
In Normal, Super Unique monsters can get up to three modifiers, applied in the order set by SuperUniques.txt; Unique monsters gets a random modifier selected from those listed in MonUMod.txt. Both get another random modifier in Nightmare, and yet another in Hell. A Super Unique monster's set modifiers are applied first, followed by any random modifiers; for both Super Unique and Unique monsters, modifiers are displayed in the order in which they are applied. For more details, see here and here.
Reducing Resistances and Breaking Immunities
Resistances can be reduced to an absolute minimum of -100% by certain skills, and items with the -% to Enemy Resistance modifier. Immunities can be broken by reducing resistance to less than 100% with some of these skills (at 1/5 effectiveness), and certain positive resistances and immunities are ignored by certain skills i.e. a monster has 0% resistance, unmodified by either inherent or acquired values.
When an Assassin or Barbarian wields two weapons, the -% to Enemy Resistance modifiers of both will be applied to any attack or spell. For more details, see here and here.
| 99% | 1% | (1/100) |
|---|---|---|
| 98% | 2% | (1/50) |
| 95% | 5% | (1/20) |
| 90% | 10% | (1/10) |
| 80% | 20% | (1/5) |
| 75% | 25% | (1/4) |
| 66% | 33% | (1/3) |
| 50% | 50% | (1/2) |
| 0% | 100% | (1) |
| -100% | 200% | (2) |
To demonstrate the effect reducing resistance can have (particularly after breaking immunity), to the right is a list of % resistance values and the percentage (and fraction) of displayed damage done.
When resistance is reduced from 99% to 98% (-1%), damage is doubled. Granted, there are diminishing returns while resistances remain positive: damage is also doubled when resistance is reduced from 95% to 90% (-5%); 90% to 80% (-10%); 75% to 50% (-25%); and 50% to 0% (-50%).
Listed below are the modifiers which apply % resistance bonuses for each damage type, and the various ways in which resistances and immunities can be reduced, broken or ignored. Note that these bonuses are only applied to the Champion or Unique monster and not to any minions. For more details, see here.
Physical
Modifiers
| 80% | Ghostly Champion |
|---|---|
| +50% | Stone Skin Unique |
A Ghostly Champion is set to 80% physical resistance (regardless of inherent resistance) unless it has an inherent physical immunity, in which case it keeps this immunity (unmodified). Bizarrely, if this immunity is broken, resistance is set to 80% and the curse (see below) is then applied to this at full effectiveness i.e. the monster has 30% resistance with Decrepify and -20% with Amplify Damage. For more details, see here.
- % to Enemy Resistance/Immunity
| -100%/-20% | Amplify Damage (Necromancer Curse) |
|---|---|
| -50%/-10% | Decrepify (Necromancer Curse) |
A Paladin's Sanctuary aura will ignore the positive physical resistance or immunity of undead; this applies to physical damage done by the supplier of the aura only. See Appendix for sources of Amplify Damage, Decrepify and Sanctuary.
Sanctuary's ignoring of the positive physical resistance or immunity of undead is applied after that of AD or Decrepify, meaning that if AD or Decrepify have already reduced physical resistance to 0% or less, Sanctuary becomes redundant. Conversely, if AD or Decrepify have not already reduced physical resistance to 0% or less, their reduction becomes redundant (since Sanctuary would have reduced physical resistance to 0% anyway). For more details, see here.
Sanctuary does not ignore positive physical resistance or immunity of undead for Crushing Blow. For more details, see here.
Counters
Curses are ineffective against Possessed Champions or Monsters That Cannot be Cursed.
Magic
Modifier
| +20% | Mana Burn Unique |
|---|
-% to Enemy Resistance/Immunity
Magic resistance or immunity cannot be reduced or broken by any means.
Magic resistance and immunity is ignored by certain Paladin skills; Holy Bolts (whether from Holy Bolt or Fist of the Heavens) ignore those of undead (although the pulse damage of the Sanctuary aura does not) whereas Blessed Hammer ignores those of both undead and demons.
Elemental (Fire, Lightning and Cold)
Modifiers
| +20% | Spectral Hit Unique (<75% Resistance) |
|---|---|
| +40% | Magic Resistant Unique (<100% Resistance) |
| +75% | Fire/Lightning/Cold Enchanted Unique |
Spectral Hit applies to each elemental resistance individually if each is less than 75% i.e. a monster with 25% fire, 50% lightning and 75% cold resistance would have 45% (25 + 20) fire, 70% (50 + 20) lightning and 75% (75 + 0) cold resistance. For more details, see here.
Magic Resistant also applies to each elemental resistance individually if each is less than 100% in the order of cold, fire and then lightning. For more details, see here.
The % resistance bonuses of Elemental enchantments only apply to the relevant element.
-% to Enemy Resistance/Immunity
| -30-150%/-6-30% | Level 1-25 Conviction (Paladin Aura) |
|---|---|
| -31-70%/-6-14% | Level 1-60 Lower Resistance (Necromancer Curse) |
| -20-200%/0% | Level 1-37 Cold Mastery (Sorceress Skill) |
Cold Mastery only applies to the cold resistance of monsters attacked by the Sorceress. Elemental resistances can also be reduced by items with -% to Enemy Fire/Lightning/Cold Resistance modifiers, which are only effective for the equipping character/hireling; they are also ineffective with certain skills, such as an Assassin's fire and lightning Traps (excluding Fire Blast and Shock Web) and a Necromancer's Fire Golem.
When Conviction and Lower Resistance are applied together, both are still applied at 1/5 effectiveness, even if either one of them is able to break immunity by itself. See Appendix for sources of Conviction and Lower Resistance.
Counters
Lower Resistance is ineffective against Possessed Champions or Monsters That Cannot be Cursed.
Conviction is ineffective against a Unique monster enchanted with a higher level Conviction aura (monster level/8); however, it is still effective against all other monsters within its radius. For more details, see here.
Poison
Modifier
| +75% | Super Unique |
|---|
Poisonhit is a modifier in MonUMod.txt but is not among those that can be applied randomly and it is not displayed. According to SuperUniques.txt, the only Super Unique monster to have it is Achmel the Cursed, the Unraveler that spawns in Baal's second wave of minions in the Throne of Destruction. Lilith is also alleged to spawn with it, although this is unconfirmed.
-% to Enemy Resistance/Immunity
| -31-70%/- 6-14% | Level 1-60 Lower Resistance (Necromancer Curse) |
|---|
Poison resistance can also be reduced by items with the -% to Enemy Poison Resistance (EPR) modifier, which is only effective for the equipping character/hireling; it is ineffective with a Druid's Poison Creeper, though. See Appendix for sources of Lower Resistance.
A monster's % poison resistance only reduces displayed poison damage, it does not reduce displayed poison length i.e. it doesn't apply any Poison Length Reduced by % (PLR) modifier. Lower Resistance only negates % poison resistance, but - % EPR negates both % poison resistance and PLR %; actual poison length = displayed poison length x (1 - (PLR % - % EPR)/100). Like % poison resistance, PLR % can be reduced to an absolute minimum of - 100% i.e. poison length can, at most, be doubled. For more details, see here.
Unlike players, monsters neither have nor can normally acquire PLR %. The only skill that grants PLR % is a Paladin's Cleansing aura, and monsters do not normally spawn with equipment; nor are any penalties applied in later difficulties i.e. monsters always have PLR 0%. The only exceptions are the Ancients, two of whom (Talic and Korlic) can spawn with equipment granting them PLR 100+%; this results in a poison immunity that is unbreakable by any amount of -% EPR (zero length = zero damage). For more details, see here.
While both Lower Resistance and -% EPR need to be applied at the same time as the poison damage to take effect, once applied they can be removed i.e. Lower Resistance can be overwritten and you can switch weapons. -% EPR does not increase the infection length of Rabies and has a variable effect on its poison length; due to the spread of infection and its mechanics, -% EPR may need to remain active for the full length of Rabies for maximum effectiveness (although the precise mechanics of Rabies are not properly understood). For more details, see here. See Appendix for sources of Lower Resistance.
Counters
Lower Resistance is ineffective against Possessed Champions or Monsters That Cannot be Cursed.
Hell Immunities.xls
I have compiled a spreadsheet of monster resistances and immunities in Hell, sorted by area and immunity. Download hell_immunities.zip (courtesy of RTB).
If you don't have Microsoft Excel, you can try a free download of Excel Viewer 2003 or OpenOffice.
Acknowledgements
Thanks to DPTR and RTB for hosting Hell Immunities.xls, and DPTR and Dida for providing links to Excel Viewer and OpenOffice.
This guide is based on this earlier post and the testing that followed in that topic, which was inspired in turn by the wealth of conflicting and ambiguous information on monster resistances and immunities (although most of the information in this guide and the testing done to verify it is neither new nor original).
Earlier testing and investigation was undertaken by brianc84, Jarulf, Atair (as reported by Librarian), Necrochild313, Nefarius and Orphan.
- rykros1987 and JesusFreak197 challenged of an earlier (and incorrect) statement of how the Ghostly modifier is applied to Champions, leading to testing that established how it is actually applied; it also inadvertently led to a proper understanding of the Spectral Hit and Magic Resistant modifiers, courtesy of Jarulf and Atair.
- BIGeyedBUG clarified how Sanctuary interacts with AD and Decrepify.
- Dida drew attention to Orphan's tests indicating that Sanctuary's ignoring of positive physical resistance and immunity of undead doesn't apply to Crushing Blow.
- librarian posted Atair's findings, and helped to investigate the mechanics of Conviction and exactly which monsters cannot be cursed.
- brianc84 established exactly which monsters cannot be cursed, and why not.
- storm-surfer prompted investigation of issues relating to poison length.
- RTB confirmed that the Ancients can indeed spawn with equipment, giving them access to PLR %.
- adeyke pointed out why -% to Enemy Resistance and +% to Skill Damage modifiers on both weapons are applied when dual-wielding (and reminded me that I don't have to test everything if I know where to look in the game files).
Other Resources
- Bosses section of librarian's FAQtoids
- Grimborn's Guide to Boss Mods
- Monster section of D2Wissen (German)
- Monsters section of the Arreat Summit
Appendix
Listed below are sources of the various skills that can break immunities and lower resistance.
Amplify Damage
At level 1, a Necromancer's Amplify Damage (AD) Curse applies -100% to physical resistance (-20% vs immunity) in a 2 yard radius around the target for 8 seconds; only the radius and duration increase, by 2/3 yard and 3 seconds per level. Below is a list of other sources of AD:
- Magic/rare/crafted weapon (excluding Orbs) with the Amplify Damage suffix (affix level (alvl) 3, no required level (rlvl)): 5% Chance to Cast Level 1 AD on Striking (2 yards, 8 seconds)
- The Vile Husk Tusk Sword: 6% Chance to Cast Level 1 AD on Striking (2 yards, 8 seconds)
- Witchwild String Short Siege Bow: 2% Chance to Cast Level 5 AD on Striking (4 2/3 yards, 20 seconds)
- The Gavel of Pain Martel de Fer: 3 level 8 AD charges (6 2/3 yards, 29 seconds)
- Atma's Scarab Amulet: 5% Chance to Cast Level 2 AD on Striking (2 2/3 yards, 11 seconds)
- Lacerator Winged Axe: 33% Chance to Cast Level 3 AD on Striking (3 1/3 yards, 14 seconds)
Ladder Only
- Brand 'JahLoMalGul' (cross)bow: 35% Chance to Cast Level 14 AD When Struck (10 2/3 yards, 47 seconds)
Decrepify
At level 1, a Necromancer's Decrepify Curse applies -50% to physical resistance (-10% vs immunity) in a fixed 4 yard radius around the target for 4 seconds; only the duration increases, by 0.6 seconds per level. Below is a list of other sources of Decrepify:
- Spellsteel Bearded Axe: 30 level 3 Decrepify charges (5.2 seconds)
- The Fetid Sprinkler Holy Water Sprinkler: 5% Chance to Cast Level 1 Decrepify on Striking (4 seconds)
Ladder Only
- Lawbringer 'AmnLemKo' sword/hammer/scepter: 20% Chance to Cast Level 15 Decrepify on Striking (12.4 seconds)
- The Reaper's Toll Thresher: 33% Chance to Cast Level 1 Decrepify on Striking (4 seconds)
- Executioner's Justice Glorious Axe: 50% Chance to Cast Level 6 Decrepify When You Kill an Enemy (7 seconds)
- Wrath 'PulLumBerMal'(cross)bow: 30% Chance to Cast Level 1 Decrepify on Striking (4 seconds)
Sanctuary
At level 1, a Paladin's Sanctuary aura ignores the positive physical resistance or immunity of undead in a 3.3 yard radius around the Paladin; this radius increases by 2/3 yard per level. Below is a list of items which apply a Sanctuary Aura When Equipped:
Ladder Only
- Lawbringer 'AmnLemKo' sword/hammer/scepter: Level 16-18 (13 1/3-14 2/3 yards)
- Azurewrath Phase Blade: Level 10-13 (9 1/3-11 1/3 yards)
Conviction
At level 1, a Paladin's Conviction aura applies -30% to elemental resistances (-6% vs immunities) in a fixed 13.3 yard radius around the Paladin; this increases by -5% (-1% vs immunities) per level, up to a maximum of -150% (-30% vs immunities) which is reached at level 25.
An Infinity 'BerMalBerIst' polearm (Ladder only) is the only other source, which applies Level 12 Conviction Aura When Equipped (-85%/-17% vs immunities).
Lower Resistance
Level 1 LR applies -31% to elemental and poison resistances (-6% vs immunities) in a 4 2/3 yard radius around the target for 20 seconds; the radius and duration increase, by 2/3 yard and 2 seconds per level, but the Resist -% is subject to diminishing returns:
| Level | Resist -% | Immunity -% | Yards | Seconds | |
|---|---|---|---|---|---|
| 1 | 31 | 6 | 4 | 2/3 | 20 |
| 2 | 37 | 7 | 5 | 1/3 | 22 |
| 3 | 41 | 8 | 6 | 24 | |
| 5 | 47 | 9 | 7 | 1/3 | 28 |
| 7 | 51 | 10 | 8 | 2/3 | 32 |
| 10 | 55 | 11 | 10 | 2/3 | 38 |
| 15 | 60 | 12 | 14 | 48 | |
| 26 | 65 | 13 | 21 | 1/3 | 70 |
| 60 | 70 | 14 | 44 | 138 | |
Below is a list of other sources of LR:
- Magic/rare/crafted dagger/shrunken head/wand with the LR suffix (alvl 36, rlvl 36): 67 level 1 LR charges; 75 level 2 LR charges (item level (ilvl) 76+); 82 level 3 LR charges (ilvl 99)
- Magic/rare/crafted staff with the LR suffix (alvl 72, rlvl 72): 22 level 1 LR charges
- Pus Spitter Siege Crossbow: 4% Chance to Cast Level 1 LR on Striking
- Medusa's Gaze Aegis: 10% Chance to Cast Level 7 LR When Struck
