List of features and items that affect attack rolls

This is a comprehensive list of all sources of effects that directly affect attack rolls.

Items

Item	Attack roll bonus	Affects
Mask of Soul Perception	2	All attacks
Legacy of the Masters	2	All attacks
Horns of the Berserker	2	All attacks while being under max HP
Winkling Gloves	1	All attacks
Bhaalist Gloves	1	All attacks
Gauntlets of the Warmaster	1	All attacks
Gloves of Dexterity	1	All attacks
Blackguard's Gauntlets	1	All attacks
Unwanted Masterwork Gauntlets	1	All attacks
Gloves of The Duellist	2	Melee attacks with one-handed weapons when not duel wielding
Marksmanship Hat	1	Ranged weapons, ranged spells, and throwing attacks
Corellon's Grace	1	Unarmed attacks
Dark Displacement Gloves	1	Throwing attacks
Sword of the Emperor	1d4	All attacks against shapeshifted or polymorphed creatures
Bow of the Banshee	1d4	All attacks against frightened targets
Monster Slayer Glaive	1d4	All attacks against monstrosities
Circlet of Hunting	1d4	All attacks against marked targets
Phalar Aluve	1d4	All attacks by allies within 9 m / 30 ft for 5 turns after using  Phalar Aluve: Sing
Cerebral Citadel Gloves	1d4	All attacks for 3 turns after inflicting frightened
Rhapsody	1, 2, or 3	All attacks
Gauntlets of Surging Accuracy	1d4	All attacks for the rest of the turn after using  Action Surge
Mutilated Carapace	1	All attacks while shapeshifted or disguised
Ritual Dagger	1d4	All attacks after attacking with the dagger or using  Blood Sacrifice

Spells

Item	Attack roll bonus	Affects
Bless	1d4	All attacks by affected creatures
Magic Weapon	1, 2, or 3	Attacks with the enchanted weapon
Elemental Weapon	1	Attacks with the enchanted weapon
Draconic Elemental Weapon	1	Attacks with the enchanted weapon
Elemental Age	1	Attacks with the enchanted weapon