Binding of Isaac: Rebirth Wiki

Added in Repentance

Berserk! is an unlockable activated item added in The Binding of Isaac: Repentance.


  • When used, gives Isaac +0.4 speed, +3 flat damage, and increases tears for 5 seconds, during which time he is restricted to using a jaw bone to damage enemies instead of his tears for 5 seconds, similarly to The Forgotten The Forgotten's bone club.
    • The jaw bone deals 3x Isaac's damage when swung and 1.5x Isaac's damage per tick when thrown (3x Isaac's damage per second).
    • The swung jaw bone reflects enemy shots.
    • The thrown jaw bone charges very quickly compared to the Forgotten's bone club, but as berserk only lasts five seconds, it uses a noticeable amount of the effect's limited duration to charge and throw the jaw bone.
    • While Berserking, Isaac's fire rate is halved then increased by 2. This will be a tears upgrade unless Isaac already has a lot of tears upgrades.
      • If playing as The Forgotten, the x0.5 fire rate modifier isn't applied, as he already has it.
    • Killing an enemy while "Berserking" increases Berserk's current duration by 1 second.
    • Killing an enemy grants very brief invincibility, preventing damage from exploding enemies.
    • Every enemy killed will also grant +0.4 speed until the effect ends.
    • Isaac is unable to die while Berserk is active. He can be reduced to 0 hearts, but will not die until the effect ends.
      • This does not apply to Damocles Damocles. The sword will kill Isaac even if Berserk is active at the time it falls.
  • This item charges when Isaac deals damage to enemies rather than by clearing rooms or picking up batteries. It requires a base total of 120 damage, and increases by 40 for every next floor.


  • The jaw bone has all the same synergies that The Forgotten's bone club does.
    • Mom's Knife Mom's Knife: While the synergy between Mom's Knife and the Berserk state is identical to The Forgotten's melee attack, it is worth noting that the attack no longer deflects enemy shots.


  • Book of Virtues Book of Virtues: Spawns a pale wisp on the middle ring. The wisp has extra HP and does not shoot.
  • Suplex! Suplex!: When used near the end of the Berserk state (any time after the second bell ring), Suplex receives a unique visual effect, and will deal massive damage to the target, while setting off a Mama Mega! Mama Mega! style explosion, destroying all obstacles in the current room and blowing open all doors. The target being Suplexed, as well as nearby enemies, will receive 300 base damage that scales with Isaac's size. All other enemies receive 200 flat damage.
  • The Lost The Lost / Tainted Lost Tainted Lost: This can allow either variant of The Lost to survive being damaged if it happens while Berserk is active. Despite having no visible health bar, their health is normally set to half a soul heart. If they take damage while Berserk is active, they will not die if they are able to pick up a soul heart or half soul heart before the effect ends.
  • The Ludovico Technique The Ludovico Technique: While under the Berserk state you lose control of the Ludovico Technique tear which can now be deflected by the jaw bone swing, bouncing off nearby walls and dealing damage to enemies.


  • 4.5 Volt 4.5 Volt / 9 Volt 9 Volt / Jumper Cables Jumper Cables: No effect.
  • Car Battery Car Battery: Duration is only extended if no enemies are killed during the first half, thus only providing a benefit against bosses that can't spawn enemies.
  • Sharp Plug Sharp Plug: Isaac will take damage without gaining any charges.

In-game footage[]


  • The item's name, description, and effects are likely a reference to the Berserk power-up from the Doom franchise.
    • The phrase 'rip and tear' is frequently used throughout the Doom franchise, and was first used in the 1996 Doom comic after protagonist Doomguy picked up the Berserk power-up.
    • In addition, Isaac's inability to die during the effect could be a reference to the common joke of the main character of the Doom franchise being "literally too angry to die."
    • May be a reference to a character Chicken from Nuclear Throne who, unlike other characters in the game, wields a katana and upon losing all HP, instead of immediately dying, her head gets cut off and she can restore health in a short amount of time to stay alive before dying for good.
    • May also be a reference to the "Rage Beyond Death" ability with similar effects that Barbarians can gain in 5th edition Dungeons & Dragons, as the original Isaac characters were modeled after character classes from the game.
  • The jawbone Isaac uses is a Donkey's jawbone, which is a reference to a passage from the Book of Judges in which Samson kills one thousand Philistines using only the jawbone of a donkey.
    • It may also be a reference to the item Donkey's Jawbone from Antibirth that didn't make the cut for Repentance.
    • This event is also referred to by the pickup message for the Soul of Samson Soul of Samson — "Slay a thousand".
  • This item's special synergy with Suplex! Suplex! was inspired by a bug in Repentance's initial release where any enemy (including final bosses like Hush Hush and Delirium Delirium) that Suplex! was used on as Berserk!'s timer was ending would be instantly killed.