Object properties

In many variants of NetHack, an object property is a magical attribute associated with a non-artifact item which does not normally have that property; for example, a leather cloak of fire resistance would have the "fire resistance" property. Only weapons (including weapon-tools), armor, rings, and amulets can have object properties.

GruntHack

In GruntHack, randomly generated objects have a 1 in 100 chance of being generated with at least one property. A wish can apply a single non-detrimental property to the object wished for. Of those objects, each has a recursive 1 in 250 chance of having an additional property applied to it.

Wizards can sense object properties before they are identified, and see a "magical" prefix before the relevant properties are known.

Item properties

• Reflection: Grants reflection. Not applicable to projectile weapons, boots, gloves, or helmets.
• Searching: Grants automatic searching. Not applicable to projectile weapons.
• Warning: Grants warning. Not applicable to projectile weapons.
• Stealth: Grants stealth.
• Telepathy: Grants extrinsic telepathy, as the helm of telepathy or amulet of ESP. Not applicable to projectile weapons.
• Fumbling: Grants fumbling.
• Hunger: Grants hunger.
• Aggravation: Grants aggravate monster.

Weapon-specific properties

• Fire: Deals double fire damage to targets without fire resistance, and has a chance of destroying potions, scrolls, and spellbooks.
• Frost: Deals double cold damage to targets without cold resistance, and has a chance of destroying potions.
• Vorpal: Single-handed weapons behead non-headless targets on a 1-in-20 chance (and jabberwocks 100% of the time), as with Vorpal Blade; double-handed weapons bisect small creatures and cut deeply into large creatures on a 1-in-20 chance, as with The Tsurugi of Muramasa. Only applicable to bladed weapons.
• Thirsty: Drains life of targets without drain resistance, as with Stormbringer and The Staff of Aesculapius.
• Detonation: Explodes in a 3x3 radius on contact after being fired or thrown. Only applicable to projectiles and launchers.

Note that in the very last development version of GruntHack, the extra fire and frost damage was changed from 2x to d6. This is the version of object properties that was incorporated in DynaHack. The version of GruntHack that can be played on grunthack.org does not have these changes.

Armor-specific properties

• Fire resistance: Grants fire resistance.
• Cold resistance: Grants cold resistance.
• Drain resistance: Grants drain resistance.
• Speed: Grants extrinsic speed, as boots of speed.
• Oilskin: Permanently greased, as the oilskin cloak. Note: for wishing purposes in Grunthack, the base material must be cloth to get oilskin.
• Power: Sets strength to 25, as gauntlets of power.
• Dexterity: Grants a +(enchantment) bonus to dexterity, as gauntlets of dexterity.
• Brilliance: Grants a +(enchantment) bonus to intelligence and wisdom, as a helm of brilliance.
• Displacement: Grants displacement, as the cloak of displacement.
• Clairvoyance: Grants clairvoyance, as though wearing a cornuthaum as a wizard.

dNetHack

dNetHack uses a completely different version of object properties compared to most other variants. Objects with properties cannot be wished for, and for the most part cannot be added to existing objects. They are primarily found in the initial inventories of certain monsters, and are also generated during the creation of certain special rooms and levels. Most properties appear in the item name when identified, but some will appear when unidentified as well.

Offensive

Most damage-enhancing properties add bonus damage of a certain type, often equal to base damage, to the object when used as a weapon - for example, a flaming long sword would deal (1d8 + enchantment) physical damage and (1d8 + enchantment) fire damage versus small monsters. This includes specific non-weapon objects that are also valid for weapon attacks, e.g. boots for kicking attacks and gloves for unarmed (i.e. bare-handed) attacks. Some of these properties also have a weaker form as well, which usually deals +2d6 damage instead.

These bonuses only apply if the object is a valid weapon (e.g. a flaming newt corpse grants no bonuses), and are additive with other attack bonuses rather than multiplicative.

• Flaming: The object deals +1x base damage as fire damage, which can destroy flammable items in the target's inventory, and deals an additional +1x base damage to fire-vulnerable targets (i.e. 3x to monsters that have cold resistance but not fire resistance).
  • Red-hot: A weaker form of flaming that deals +2d6 damage and can destroy flammable items.
• Freezing: The object deals +1x base damage as cold damage, which can destroy freezable items in the target's inventory, and deals an additional +1x base damage to cold-vulnerable targets (i.e. 3x to monsters that have fire resistance but not cold resistance).
  • Frosted: A weaker form of freezing that deal +2d6 damage and can destroy freezable items.
• Shocking: The object deals +1x base damage as shock damage, which can remove one or more charges from wands in the target's inventory.
  • Sparking: A weaker form of shocking that deals +2d6 damage and can remove wand charges.
• Sizzling: The object deals +1x base damage as acid damage, which can destroy a single potion in the target's inventory.
  • Acrid: A weaker form of sizzling that deals +2d6 damage and can destroy a potion on each hit.
• Sparkling: The object deals +1x base damage as magic damage (the same as magic missile, which checks for player-style magic resistance).
  • Glittering: A weaker form of sparkling that deals +3d4 damage.
• Misty: The object deals +1x base damage as water damage, which is resisted by waterproofing (e.g. oilskin, white dragon scales, etc.), and deals an additional +1x base damage (i.e. 3x total) to flaming monsters, earth elementals, iron golems, and chain golems.
  • Damp: A weaker form of misty that deals +2d6 damage.
• Psionic: The object deals +1x base damage with an additional damage bonus equal to enchantment (i.e. 3x enchantment and 2x base damage) to telepathic creatures. A psionic item used as a weapon also has a ¹⁄₅ chance of triggering versus non-telepathic, non-mindless creatures. Appears when telepathic (even when not blinded) or when fully identified; when not fully identified but seen via telepathy, appears as "whispering" instead of "psionic".
  • Rustling: A weaker form of psionic that deals +2d12 damage, with the same rules for vulnerable targets as psionic. Appears only when telepathic, even if fully identified.
• Anarchic: The object deals +1x base damage to non-chaotic targets. Only appears when the object is fully identified.
  • Unruly: A weaker form of anarchic that deals +2d6 damage to non-chaotic targets. Only appears when the object is fully identified.
• Concordant: The object deals +1x base damage to non-neutral targets. Only appears when the object is fully identified.
  • Accordant: A weaker form of concordant that deals +2d6 damage to non-neutral targets. Only appears when the object is fully identified.
• Axiomatic: The object deals +1x base damage to non-lawful targets. Only appears when the object is fully identified.
  • Apodictic: A weaker form of axiomatic that deals +2d6 damage to non-lawful targets. Only appears when the object is fully identified.
• Forge-hot: The object deals +1d8 fire and +1d8 axiomatic damage.
• Crystalline: The object deals +1d8 cold and +1d8 axiomatic damage.
• Arcing: The object deals +1d8 shock and +1d8 axiomatic damage.
• Holy: When blessed, a holy object deals +1x base damage to targets vulnerable to blessed damage. Appears when blessed with "holy" replacing "blessed" in the object's name, but doesn't require the object to be fully identified.
  • Consecrated: A weaker form of holy that deals +2d6 damage and appears with the same rules as holy.
• Unholy: When cursed, an unholy object deals double damage to targets vulnerable to cursed damage. Appears when cursed with "unholy" replacing "cursed" in the object's name, but doesn't require the object to be fully identified.
  • Desecrated: A weaker form of unholy that deals +2d6 damage and appears with the same rules as unholy.
• Flaying: A flaying object breaks armor off struck targets, damaging a random piece of worn armor 1+d4 times; if the armor's protection is reduced to 0, it will be destroyed. If the monster has no armor left, living monsters without thick skin will "scream from the pain" and be slowed by 6 movement points. Only appears when the object is fully identified.
  • Excoriating: A weaker form of flaying that damages worn armor by 1 point, and slows unarmored targets for 2 movement points. Only appears when the object is fully identified.
• Morgul: When a morgul object hits you, it embeds a morgul-blade shard in you. When used versus a monster, it drains their current and maximum HP by 1d4, bypassing drain resistance. Morgul shards abuse your constitution, wisdom, and charisma, killing you if they bring all of those stats below their minimums.
  • Morgul-shard: A weaker form of morgul, a morgul-shard object that hits you only embeds a shard if one was not already present. Against a monster, it drains their current and maximum HP by 1.
• Wrathful: When used to kill a monster, the object gains a +0.25 damage bonus versus that monster type (stacking to a cap of 4 kills and 2x damage) until you kill a monster of a different type. This damage applies to all monsters of that kind, based on factions (zombified, skeletons, etc.), racial flags (demons, humans, etc.), or just the exact same monster.
• Faded: The object is treated as an armor-phasing weapon, which bypasses the AC and DR of the target's worn armor and always hits insubstantial targets such as shades.
• Vorpal: The weapon can decapitate/bisect/etc. monsters with a ¹⁄₂₀ chance. The vorpal type is chosen based off the object's damage types. Weapons that deal both slashing and piercing damage will decapitate the target, slashing-only will bisect the target, piercing-only will pierce the target's heart or heart-equivalent, and bludgeoning will smash the target flat. Only appears when fully identified.
• Deep: The weapon has a ¹⁄₄₀ chance per turn of emitting a level-wide damaging mind blast, targeting you and other monsters. The mind blast's damage die size and amount increases inversely based on its enchantment, and is represented by the equation 15 - 2x where x is the enchantment of the weapon - this also determines the amount of dice used: 1 die for a result of 1-5 (1.e. +5 to +7), 2 dice for 6-10 (+3 to +4), 3 dice for 11-14 (+1 to +2), and 5 dice at 15 or more (+0 and below).
  • At +2 enchantment or lower, a deep weapon's mind blasts that hit you will either awaken all monsters or any monsters with telepathy on the level and reveal your location, similar to a cursed potion of invisibility - it additionally encourages them and provides a morale-style boost to damage and accuracy, equal to the amount of damage done divided by the amount of damage dice (effectively the average of those dice rolls). Deep weapon mind blasts that hit monsters at this enchantment will inflict the studied status on them for duration to a length equal to the amount of damage done, unless that amount is lower than their current studied duration.
  • At +0 enchantment or lower, a deep weapon's mind blasts have a ¹⁄₂₀ chance of occurring each turn. Mind blasts that hit you will stun you for 10 turns per point of damage in addition to the above, while monsters hit by the mind blast are confused in addition to the above.
• Self-acidifying: The object has a 2.5% chance of coating itself in acid each turn, which adds +1d10 acid damage and stacks with sizzling and acrid properties. This only appears when the object is not acid-coated, and appears as "acid-secreting" when above 10 insight.
• Loyal: The weapon returns when thrown, similar to Mjollnir or any weapon thrown by Androids. This only appears as "loyal" when above 10 insight, and otherwise appears as "returning".
• Life-drinking: The weapon drains an experience level or monster level from the victim on each hit, similar to Stormbringer.

Defensive

These are exclusively extrinsic properties applied to items in any worn slot, including rings, amulets, and wielded items; items twoweaponed in the off-hand do not count.

• Flameproof: Grants fire resistance. Only appears when the object is fully identified. Flameproofed items are immune to fire damage.
• Coldproof: Grants cold resistance. Only appears when the object is fully identified.
• Voltproof: Grants shock resistance. Only appears when the object is fully identified.
• Acidproof: Grants acid resistance. Only appears when the object is fully identified.
• Magic-resistant: Grants magic resistance. Only appears when the object is fully identified.
• Disintegration-proof: Grants disintegration resistance. Objects with this property can't be destroyed by disintegration attacks, but can be destroyed by other armor-shredding attacks. Only appears when the object is fully identified.
• Reflective: Grants normal reflection.
• Woolen: Grants both fire and cold resistance. Woolen items are immune to fire damage.
• Prayer-warded: Blocks effects that curse inventory items (such as the curse items monster spell). Also protects against mummy curses.
• Healing: Periodically heals the wearer with a ~0.5% to ~2% chance per turn; the healing effect occurs more often when the wearer is below 50% hp and when enemies are nearby. The healing restores 5d8 HP, with no more than half of the wearer's lost HP healed this way, and has a 5% chance per turn of healing sickness and sliming. Only appears as healing if fully identified; above 20 insight, it appears as "angel-haunted" (or "angel-imprisoning" if cursed).
• Life-saving: If the wearer dies, their life will be saved, as with an amulet of life saving; the property will trigger after an actual amulet of life saving, but before any other sources of the property such as a ring of wishes or Jack. The item will lose the property after it is triggered, but otherwise remains intact. On objects that are not fully identified, it appears as "haloed" on helmets, "gold-feather-encrusted" on silver items, and "silver-feather-encrusted" on other items.
• Self-greasing: The object has a ¹⁄₄₀ chance of greasing itself each turn if not greased. Only appears when the object is not greased. Appears as "grease-secreting" when above 10 insight.
• Anarchic: Grants double DR vs lawful and neutral attackers, but only half DR vs chaotic attackers. Only appears when the object is fully identified.
• Concordant: Grants double DR vs lawful and chaotic attackers, but only half DR vs neutral attackers. Only appears when the object is fully identified.
• Axiomatic: Grants double DR vs neutral and chaotic attackers, but only half DR vs lawful attackers. Only appears when the object is fully identified.
• Holy: When blessed, grants double DR vs. holy-hating attackers, but only half DR vs unholy-hating attackers. Only appears when the object is fully identified.
• Unholy: When cursed, grants double DR vs. unholy-hating attackers, but only half DR vs holy-hating attackers. Only appears when the object is fully identified.

Other

These qualities are similar to object properties, and can apply to weapons and armor alike.

• Bladed: Bladed armor and weapons deal slashing damage in addition to their normal base damage type(s).
• Spiked: Spiked armor and weapons deal piercing damage in addition to their normal base damage type(s).

DynaHack

DynaHack works mostly similar to GruntHack, with some caveats:

• All players can sense object properties regardless of role.
• Vorpal no longer randomly generates.
• Weapons and weapon-tools get properties (level difficulty)/100 of the time.
• Armor gets properties ¹⁄₁₀₀ of the time, similar to GruntHack.
• Jewelry gets properties ¹⁄₂₅₀ of the time, except for the Amulet of Yendor.
• Only magical wishes can apply an object property, and even then they can only be applied on non-magical base items. Oilskin doesn't count as an innate power, as it does not change player attributes - note that "oilskin cloak of displacement" is parsed as a cloak of displacement with the oilskin property, and thus counts as wishing for an object property to be applied; the proper syntax is instead "slippery cloak of displacement".

FIQHack

FIQHack object properties are as follows, with some cues and differences from those of GruntHack and DynaHack:

• Vorpal does not generate randomly.
• Weapons and weapon-tools get properties (level difficulty)/100 of the time, much like DynaHack.
• Magical armor gets properties half as often as weapons, and jewelry gets properties 1/4 as often.
• Bags and armor can generate with the oilskin property, with equal probability as weapons getting properties.
  • Wearing armor with the oilskin property protects the wearer and their items from water damage.
  • Bags with the oilskin property protect their contents from water damage, in addition to their base properties.
• The following properties generate 10% as often: reflection, telepathy, speed, power, dexterity, brilliance, displacement
• Added properties:
  • Lightning: Deals +d6 shock damage to non-shock-resistant targets; has a chance of destroying wands.
  • Shock resistance: Grants shock resistance.
  • Mercy: autocurses and converts damage to healing, healing the opponent the equal amount as it would otherwise have damaged
  • Carrying: increases carrying capacity by +10%, per item of carrying. Generates on armor only.
  • Nasty: Deals +2d6 damage, but does 1d6 to the user on each melee hit or miss. Generates on melee weapons.
• Added container-only properties:
  • Greed: Makes gold inside weightless, but causes 50% of attempts to take things out to fail.
  • Discovery: Automatically reveals the base type of stashed items.
  • Refrigeration: Only appears on containers, and prevents stashed corpses from rotting.
• You cannot wish for properties at all. However, you can add or remove properties using a potion of wonder (which can be wished for).
• Weapons can no longer generate with fumbling, but armor still can.
• "Properties applicable to most or all items" no longer includes projectile weapons, which only can have fire, cold, shock, thirsty or detonation.
• Detonations are fire-based by default; they become cold-based with weapons of frost, and lightning-based with weapons of shock.
• Price-wise, if an object has any property, its base price is increased by 50. In addition to this, each property double the overall price -- so if something's base price is 5, one property would have it at 110 ((50+5) * 2), two properties at 220 ((50+5) * 2 * 2), etc.

EvilHack

EvilHack has its own set of object properties. It is based on the GruntHack system, with significant alterations:

• There are fewer object properties and they are only applicable to weapons and armor, with the exception of artifacts, unique items and dragon scales/scale mail.
• Items with object properties are less likely to be found in the dungeon, but can appear randomly on eligible magical items, and are more likely to occur with higher-level objects.
  • The odds of an eligible item having a magical property are ¹⁄₁₅₀, and those odds improve with dungeon depth. For player monsters, the odds of their weapon having a magical property is ¹⁄₂₀ if they are of a high enough level or are encountered on the Astral Plane. Angelic beings flagged as M2_LORD have a 1 in 16 chance of their long sword being generated with a magical property.
  • Regular armor and weapons obtained via sacrifice gift have a ¹⁄₈ chance of being generated with a magical property, provided the player has at least five point of luck.
  • There is a ¹⁄_100,000 chance of an eligible item randomly spawning with two properties.
• A players' starting inventory will never have an object property.
• Extrinsic properties that are applied to weapons or armor are active only when those objects are wielded/worn. With weapons, extrinsic properties work in the offhand whilst twoweaponing.
• Object properties can be wished for on an eligible item, but not on an already-magical item (e.g. no wishing for a cloak of magic resistance and drain resistance). Object properties also cannot stack via wishing, e.g. you can't wish for a long sword of fire and venom.
• Changing a regular item with object properties into an artifact (e.g., dipping for Excalibur) will strip that item of its object properties.
• Wizards have an innate ability to 'sense' if an item is magical (much like a Priest knowing the beatitude of all items).

The table below lists all available magical properties, what items they can be applied to, and what their function is.

Object property	Armor	Weapon	Armor attributes	Weapon attributes
Fire	X	X	provides fire resistance	does 1d5 + 3 of extra fire damage
Frost	X	X	provides cold resistance	does 1d5 + 3 of extra cold damage
Shock	X	X	provides shock resistance	does 1d5 + 3 of extra shock damage
Venom	X	X	provides poison resistance	does 1d2 + 10% chance of an additional 6-15 of extra poison damage, has a 10% chance of instakill by poison
Decay	X		provides drain resistance
Oilskin	X		acts as being permanently greased, can only be applied to cloth armor pieces (e.g. "oilskin cloth elven helm")
ESP	X	X	extrinsic telepathy when worn	extrinsic telepathy when wielded
Searching	X	X	extrinsic searching when worn	extrinsic searching when wielded
Warning	X	X	extrinsic warning when worn	extrinsic warning when wielded
Excellence	X	X	charisma adjustment equal to the enchantment	charisma adjustment when wielded based on BUC status (25/18/6 – blessed/uncursed/cursed)
Fumbling	X		extrinsic fumbling when worn
Hunger	X	X	extrinsic hunger when worn	extrinsic hunger when wielded