Weapons
Greatsword +1 (Common): Does not provide a +1 bonus to attack and damage.
Syringe (+1): Does not provide any of it's listed weapon actions to the character wielding it.
Trepan (+1): Does not provide any of it's listed weapon actions to the character wielding it.
Artificial Leech (+1): Does not provide any of it's listed weapon actions to the character wielding it.
Bonesaw (+1): Does not provide any of it's listed weapon actions to the character wielding it.
Hellrider Longbow: The Faerie Fire effect caused by this weapon's Fiendish Fire passive can be triggered by attacking with spells, both those with attack rolls and those with saves - including area of effect spells.
Faithbreaker: The Absolute Power weapon action deals unlisted additional damage equal to your strength modifier.
Ironwood Club: Grants Ironwood Harmony when when Shillelagh is cast on it dealing 1d4 additional piercing damage, which is not shown on the weapon's tooltip anywhere.
Shining Staver-of-Skulls: The Light effect granted by this item works differently to all other equipment that provides light, and cannot be toggled off by the wielder.
Staff of Arcane Blessing: The description of Mystra's Blessing is incorrect, it only provides an additional 1d4 to spell attack rolls, giving 1d4 to attack rolls, 1d4 to saving throws and 2d4 to spell attack rolls in total. Mystra's Blessing is also only applied when casting bless as a first or second level spell.
Wulbren's Hammer: Deals an additional 2d4 force damage to objects which is not listed on the tooltip.
Bow of the Banshee: The Blood-Curdling Emission passive granted by this weapon adds it's additional attack and damage against frightened targets to all weapon attacks, not just those made by the bow itself.
Dolor Amarus: The bonus damage on critical hits from Dolor Amarus effects crits with any equipped weapon, not just the dagger.- Vicious Shortbow: The bonus damage on critical hits from Dolor Amarus effects crits with any equipped weapon, not just the shortbow.
Vicious Battleaxe: The bonus damage on critical hits from Dolor Amarus effects crits with any equipped weapon, not just the battleaxe.
Dread Iron Dagger: the bonus damage from Dread Iron Ambush effects attacks with any equiped weapon, not just the dagger.
Infernal Mace: The Infernal Weapon passive does not apply Poison.
Infernal Spear: The Infernal Weapon passive does not apply Poison.
Monster Slayer Glaive: The Monsterslayer passive provides bonus damage and attack to all attacks targetting monstrosities, instead of just damage when attacking with the weapon itself.
Rat Bat: Deals an additional 1d6 piercing damage, which is not shown on the weapon's tooltip.
The Long Arm of the Gur: The Revenant Scourge passive does nothing.- Thermodynamo Axe: Gaining heat is limited to once per attack, additional stacks are not granted by attacks that hit multiple enemies such as cleave.
Hellfire Greataxe: Gaining heat is limited to once per attack, additional stacks are not granted by attacks that hit multiple enemies such as cleave. The Roling Hellfire created by Hellflame Cleave weapon action does not ignore fire resistance despite stating it does (This may have already been fixed).
Justiciar's Scimitar: Has no proficiency requirement, allowing it to be wielded properly by any character.
Staff of Cherished Necromancy: The Life Essence Harvest passive does not correctly remove charges of Life Essence when a spell is cast for free, allowing unlimited free spellcasting of necromancy spells.
Crimson Mischief: Despite being a shortsword, characters with scimitar proficiency are also able to wield this weapon proficiently. Maybe not a bug?
Gontr Mael: The Bolt of Celestial Light weapon action incorrectly refers to Gontr Mael as Gontre Motte, it also states it will not use a superiority dice on a miss, but doesn't use superiority dice at all regardless of hitting or missing.
Shar's Spear of Evening: The bonus damage from Shar's Blessing effects attacks with any equipped weapon, not just the spear.
Clothing
Bided Time: The Time Thoroughly Bided passive grants 2 charges of Arcane Charge, not one as the tooltip implies.
Bloodguzzler Garb: The Grievous Retribution passive grants 2 charges of Wrath, not one as the tooltip implies.
Cloth Armour: The Grievous Retribution passive grants 2 charges of Wrath, not one as the tooltip implies.
Drunken Cloth: The Snowy Liver passive does not provide any temporary hitpoints.
Enraging Heart Garb: The Ruintamer Heart passive does nothing.
Garb of the Land and Sky: The Breezeswift Speed passive grants it's advantage and bonus damage to all attack rolls but is only removed on a succesful weapon attack, meaning multiple attacks per turn can be made with the bonuses. I need to test this one, not 100% certain if this has been fixed.
Moon Devotion Robe: The Produce Flame cantrip granted by this robe always uses Wisdom as it's casting ability, unlike other spells provided by items which use the character's current spellcasting modifier. The version of produce flame granted to Asmodeus Tieflings works the same way, so this item may be using that version of the spell.
Armour
Armour of Landfall: The Green Bed Regeneration passive does nothing.
Bhaalist Armour: The Aura of Murder passive causes everyone to run away from you. Maybe not a bug but it's annoying, and they fixed summons having the same effect so maybe they'll fix this too.
Elven Chain: This armour functions the way it does by simply not having a profiency requirement, the Elven Chain (passive feature) effect is purely visual and appears to have no effect. Due to this the item allows many passives that shouldn't work when wearing armour to work regardless. This also has a secondary effect, the armour has a hidden passive to emulate the effect of the Defence fighting-style, because otherwise it would not count as armour, this hidden passive incorrectly stacks with the fighting style, allowing +2 ac if you're wearing this armour and another armour piece.
Unwanted Masterwork Scalemail: The Exotic Material passive does not function if a character has the Medium Armour Master feat, limiting them to +3 AC from dexterity.
Yuan-Ti Scale Mail: The Exotic Material passive does not function if a character has the Medium Armour Master feat, limiting them to +3 AC from dexterity.
Adamantine Scale Mail: The Adamantine Backlash passive will apply more than 2 turns of Reeling if the attack deals multiple types of damage, e.g. if an attack does piercing + fire damage, the passive will activate twice causing 4 turns of reeling.
Armour of Agility: The Exotic Material passive does not function if a character has the Medium Armour Master feat, limiting them to +3 AC from dexterity.
Sharpened Snare Cuirass: The Exotic Material passive does not function if a character has the Medium Armour Master feat, limiting them to +3 AC from dexterity. Maybe not a bug but the list of sources effected by Sharpened Snare is extremely limited.
Adamantine Splint Armour: The Adamantine Backlash passive will apply more than 2 turns of Reeling if the attack deals multiple types of damage, e.g. if an attack does piercing + fire damage, the passive will activate twice causing 4 turns of reeling.
Helldusk Armour: This armour functions the way it does by simply not having a profiency requirement, the Helldusk Armour (passive feature) effect is purely visual and appears to have no effect. Due to this the item allows many passives that shouldn't work when wearing armour to work regardless. This also has a secondary effect, the armour has a hidden passive to emulate the effect of the Defence fighting-style, because otherwise it would not count as armour, this hidden passive incorrectly stacks with the fighting style, allowing +2 ac if you're wearing this armour and another armour piece.
Shields
- The Shield Bash reaction granted by the following shields has no effect but still consumes your reaction if used.
Shield of the Undevout: The Dreadful Hewer passive also works for abilities and spells that apply Frightened (Condition)
Swires' Sledboard: The Shield Conduit passive grants 2 turns of Force Conduit, one one as the tooltip implies.
Viconia's Walking Fortress: Like shield bash, Rebuke of the Mighty does nothing.
Headwear
Hat of Storm Scion's Power: The Thunderous Acuity passive grants 2 turns of Arcane Acuity, not one as the tooltip implies.
Marksmanship Hat: The Marksmanship passive effects spell attack rolls and also does not effect off-hand ranged attack rolls.
Bonespike Helmet: The Fury In The Marrow passive actually deals no damage on a succesful save instead of half damage.
Horns of the Berserker: The Blood Thirst passive deals it's damage even at full hp for unarmed strikes. It also does not deal damage unless you are in combat.
Cloaks
Cloak of Elemental Absorption: The bonus damage granted by Absorb Elements only works for weapon attacks, despite the tooltip implying it should work for any attack.
Cloak of the Weave: The bonus damage granted by Absorb Elements only works for weapon attacks, despite the tooltip implying it should work for any attack.
Handwear
Gloves of Baneful Striking: The Baneful Strike passive reduces all of an enemies saving throws for it's duration, not just against the wearer's next spell. It also applies without a saving throw.
Ichorous Gloves: The Noxious Fumes (Condition) generated by the Ichorous Corrosion passive imply they will only effect enemies, this does not seem to be the case and they appear to damage anyone inside.
Craterflesh Gloves: The Craterous Wounds passive has it's damage increased due to being a critical hit, meaning it will always deal atleast 2d6 force damage and not the listed 1d6.
Gloves of Battlemage's Power: The Battlemage's Power does give any stacks of Arcane Acuity.
Flawed Helldusk Gloves: The bleeding effect applied by the Lesser Infernal Touch passive does not show a saving throw in the combat log, it does function correctly though.
Gloves of The Duellist: The description of the Duelling Gloves passive is incorrect, the passive still functions if a shield is equipped in your off-hand, much like the Duelling fighting style.
Helldusk Gloves: The Infernal Acuity passive also grants an unlisted +1 to weapon and unarmed attack rolls.
Spellmight Gloves:The Spellmight passive grants it's bonus damage to smites that count as spells (Such Thunderous Smite) while not reducing their accuracy.- Legacy of the Masters: The +2 to attack rolls from Arming Enhancement also applies to spells despite the description specific weapon attacks. The +2 damage is not added to spells.
Footwear
The Speedy Lightfeet: The Speedy Sparks passive can only activate once per turn, despite the description not stating this.
Amulets
Amulet of Elemental Torment: While not nescessarily aa bug, in earlier versions of the game this necklace could be sold by various Act 1 Traders, after Patch 3 however it is only availiable as a drop from Hope.
Amulet of the Drunkard: The Booze Remedy passive only grants it's healing when Drunk (Condition) is applied, not at the start of each turn while drunk.- Magic Amulet: While not necessarily a bug, the Innate Fortitude passive will prompt you to use it on every single roll, even if it is already successful, making this item very frustrating to use.
Sentient Amulet (Very Rare): The tooltip for this item states it grants Shatter as a second level spell, but the damage dealt is actually that of shatter cast as a third level spell.
Unflinching Protector Amulet: While not necessarily a bug, the Unflinching Protection passive will prompt you to use it on every attack, even if it would already miss, making this item very frustrating to use.
Rings
Sunwalker's Gift: The Sunwalker's Gift (passive feature) granted by this ring appears to do nothing.
Ring of Feywild Sparks: This ring also grants +1 to spell save DC that is not listed anywhere in it's description.