Hullbreaker

Stats

Values as the League of Legends Wiki's item data lists them, for every mode; the data doesn't state their units.

Effects

• Skipper (unique): Basic attacks on-hit against any enemy grant a stack for 10 seconds, stacking up to 5 times. At maximum stacks, or 4 stacks, your next basic attack on-hit against a champion, epic monster, or structure consumes all stacks to deal 120% base AD (+ 5% maximum health) bonus physical damage, increased to 300% base AD (+ 10% maximum health) against structures.
• Boarding Party (unique): Allied Blue Siege Minion and Blue Super Minion within er 1050 units gain 70 to 130 for 11 bonus armor and bonus magic resistance, as well as 10% increased size.³

Arena changes

• Attack damage changed to 40.
• Health changed to 500.
• New Unique Passive - Solo Party: While no allied champions are within 1500 units, gain 100 bonus armor and bonus magic resistance, decaying over 3 seconds when an ally is within range.
• Removed Unique Passive - Boarding Party.⁴

• Get Hullbreaker when you have Ethereal Weapon.⁵
• Hullbreaker, Reverberation, Titanic Hydra, and Terminus together give damage and tank stats.⁶

• Reverberation and Ethereal Weapon on crowd-control tanks can trigger Hullbreaker quickly.⁷
• Hullbreaker works with Ethereal Weapon.⁸

• Hullbreaker deals no damage on ranged champions.⁹¹⁰
• Hullbreaker's damage numbers might be visually bugged; a health item can help check whether the fifth on-hit deals more damage.¹¹

Earlier formats

• Hullbreaker was part of a Bel'Veth build for more health ratios.¹² 8x2 duos
• Hullbreaker dealt no damage on ranged champions.¹³ 8x2 duos