Doublestrike

Doublestrike
Doublestrike grants a character a chance to make an additional attack roll with their main hand weapon any time they make a main hand melee attack. The additional roll is made on the target of the inital attack. Doublestrike only applies to melee attacks.

Doublestrike was introduced as part of the Update 5 combat changes. Many attack speed bonuses were converted to Doublestrike effects at that time.

Morale Bonuses
Most bonuses from equipment and songs are Morale bonuses and do not stack with each other - only the highest will apply.
 * The Bard Warchanter II song Inspire Recklessness grants a +5% Morale bonus to Doublestrike and -10% fortification to all nearby allies.
 * 3% items:
 * As a prefix on lootgen Gloves and Rings.
 * Category:Doublestrike items/3%
 * 6% items:
 * As a prefix on lootgen Gloves and Rings.
 * Alchemical Crafting Tier 2 Martial Air effect includes a +6% bonus to Doublestrike.
 * Category:Doublestrike items/6%

Other Bonuses
These bonuses will stack with other bonuses of different types, but not bonuses of the same type.
 * The Draconic Ferocity set bonus on Flawless Black Dragon Armor/Helm of the Black Dragon grants a +3% artifact bonus to Doublestrike.
 * The Paladin spell Zeal grants a +10% Sacred bonus to Doublestrike to the caster.
 * Cannith Combat Infusion on Fabricator's Bracers grants a temporary 5% alchemical bonus to Doublestrike.

Bonuses From Feats
Bonuses from feats stack with everything unless otherwise noted.
 * The Shield Mastery / Improved Shield Mastery feats grant a +3% / +8% bonus to doublestrike while wearing a shield.
 * Opportunist, a Rogue Special Ability feat, grants a +3% bonus to Doublestrike.
 * The Natural Fighting Druid feat grants a +6% bonus to Doublestrike and can be taken up to 3 times.

Bonuses From Enhancements
Bonuses from enhancements stack with everything unless otherwise noted.
 * The Fighter Weapon Alacrity fighter capstone includes a +10% bonus to Doublestrike.
 * Monk Wind Stances grant a +2.5%/+5%/+7.5%/+10% bonus to Doublestrike.
 * The Ranger Tempest III enhancement grants a +5% bonus to Doublestrike while wielding two weapons.
 * Druid Celerity enhancement grants a +50% bonus to Doublestrike for 15 seconds; cooldown 5 minutes.

Bonuses From Epic Destinies
Bonuses from epic destinies stack with everything unless otherwise noted.
 * The Unyielding Sentinel Tier 2 ability Legendary Shield Mastery grants a +[2/4/7]% bonus to Doublestrike while wearing a shield.
 * The Shadowdancer innate ability Shadow Training IV grants a +3% bonus to Doublestrike while wielding weapons that qualify for Weapon Finesse.
 * The Grandmaster of Flowers Tier 2 ability Running with Wind grants +[1/2/3]% to Doublestrike if you are in Monk Wind Stance.
 * The Grandmaster of Flowers Tier 2 ability Hail of Blows grants +3% to Doublestrike.
 * The Legendary Dreadnought Tier 4 ability Lightning Mace can grant a +15% to Doublestrike for 6 seconds when you crit with a blunt weapon in your main hand.