Isaac (Boss)

From Binding of Isaac: Rebirth Wiki
Jump to: navigation, search
Boss Isaac name.png
Boss versus screen image
Base HPStage HP
Table dividing line 1.png
Ingame Appearance

Entity ID
Table dividing line 2.png
Found In
Stage Cathedral icon.png
Stage The Void icon.png
Table dividing line 3.png
Dropped Items
Final Boss Chest (The Chest)
Disambig.png This article is about the boss. For the character, see Isaac.

Isaac is the boss of the Cathedral Cathedral, which can be accessed by either killing Mom's Heart 11 times and proceeding to kill It Lives, or entering an Angel Room after killing Mom's Heart and walking into the beam of light that appears. It is also accessible by using a teleport item before entering the boss room on the final floor. He is the final boss of Ending 13.

Behavior[edit | edit source]

Note: During all three of Isaac's phases, he will always shoot multiple Projectiles in the player's direction at fixed intervals. After taking enough damage, he will begin to shoot double projectiles and triple projectiles.

Isaac will not begin attacking the player until he takes damage.

Phase 1

  • Shoots 10 lines of projectiles in every direction.
  • Shoots 8 groups of projectiles in a spinning pattern.
  • Shoots 8 groups of spinning projectiles along with 10 slightly curved lines of projectiles in every direction.

Phase 2

  • Shoots 4 projectiles in the cardinal or diagonal directions, which will split into four short-ranged projectiles after a short time, similar to 15►Cricket's Body Cricket's Body.
  • Shoots 8 projectiles in all directions.
  • Summons Angelic Babies in pairs.
  • Summons two beams of light, similar to the beams summoned by 15►Crack the Sky Crack the Sky.

Phase 3

  • Isaac grows angel wings and teleports off-screen and summons beams of light to cover the screen, starting from one of the top corners to the opposite bottom corner. After teleporting back on-screen, he will shoot the 10 lines of projectiles from the first phase. He will repeat this process every time he takes a certain amount of damage
  • Angelic Babies cease spawning.
  • Uses all shot patterns from the first phase.
  • Isaac will block the player by flying in front of them if they attempt to traverse behind or to the left/right of Isaac.

Gallery[edit | edit source]

Unlockable Items[edit | edit source]

  • PONG
    Added in Afterbirth † PONG - Defeat Isaac 5 times.

Also, beating Isaac with a particular character for the first time will unlock the Cross completion mark on that character's post-it note.

Strategy[edit | edit source]

Since Isaac does not attack the player until he is damaged, an effective strategy can be to use Remote Detonator after placing down many bombs. The bombs will not explode until remote detonator is used, dealing massive damage to Isaac. However, this requires the player to have a decent number of bombs (or a Golden Bomb). Having bomb synergy items (i.e. Mr. Mega, Bob's Curse, etc.) improves this strategy further.

During the second phase of the fight, attempt to damage Isaac enough to push him into his third phase as quickly as possible. The beams of lights spawned during this phase are random; the more time spent on this phase, the greater the likelihood of getting hit by them.

In Isaac's third phase, the beams of light he summons are hard to dodge, but they do have areas where damage can be greatly minimized. For example, if the beams of light start in the upper left corner, they will never hit the bottom left corner or the top right corner, but they can hit the bottom right corner. As a result, making it to a corner adjacent to where the beams begin is the optimal strategy to reduce the likelihood of taking damage from this attack, and going to the opposite corner is the next best thing as beams only sometimes hit that area. The top and bottom center of the room are also consistently safe, in case Isaac's speed cannot make it to a corner in time. Barring these strategies, running through the beams in the opposite direction they are coming from (if timed correctly) does not hurt Isaac.

Notes[edit | edit source]

Trivia[edit | edit source]

  • Isaac, along with ???, are the only bosses who do not "die" upon losing all their health. Instead of exploding into a pile of gore, Isaac teleports away and the battle ends. Oddly it's noted that Isaac's expression as the fight goes on goes from a somber, scared tone to him smiling in his third phase. This supports the theory that Isaac has made peace with himself and realized what he must do, as seen through the multiple endings of the game.
  • Isaac was added in the Wrath of the Lamb DLC for the original The Binding of Isaac.
  • The music that plays during this boss fight is titled Infanticide.[1] The term infanticide refers to the act of killing an infant or newborn.
  • During his first phase, Isaac makes the same crying sound as Mulligans. This also applies to ???.

Bugs[edit | edit source]

Bug Bug! Added in Afterbirth † The Angelic Babies always spawn in the bottom center of the room at the same position.

References[edit | edit source]

Bosses Boss Monstro.png
Chapter 1
Stage The Basement icon.pngStage The Cellar icon.pngStage Burning Basement icon.png
GeminiStevenBlighted OvumDingleThe Duke of FliesFamineFistulaGurglingsThe HauntLarry Jr.MonstroPinWidowThe FallenThe Headless Horseman
DangleLittle HornRag ManTurdlings
Baby Plum
Chapter 1.5
Stage Downpour icon.pngStage Dross icon.png
Lil BlubWormwoodThe RainmakerMin-MinClogColostomiaTurdlet
Chapter 2
Stage The Caves icon.pngStage The Catacombs icon.pngStage Flooded Caves icon.png
ChubC.H.A.D.Carrion QueenDark OneGurdyGurdy Jr.The HollowThe HuskMega FattyMega MawPeepPestilencePolycephalusThe WretchedThe FallenThe Headless Horseman
The ForsakenThe FrailThe Stain
Big HornRag Mega
Chapter 2.5
Stage Mines icon.pngStage Ashpit icon.png
Reap CreepTuff TwinsHornfelGreat GideonSingeThe ShellThe Pile
Chapter 3
Stage The Depths icon.pngStage Necropolis icon.pngStage Dank Depths icon.png
The AdversaryThe BloatThe CageThe GateMonstro IIGishLokiMask of InfamyWarThe FallenThe Headless HorsemanMom
Sisters Vis
Reap CreepThe Pile
Chapter 3.5
Stage Mausoleum icon.pngStage Gehenna icon.png
The SirenThe HereticThe VisageThe Horny Boys
Chapter 4
Stage The Womb icon.pngStage Utero icon.pngStage Scarred Womb icon.png
BlastocystThe BloatConquestDaddy Long LegsTriachnidDeathLokiiMama GurdyMr. FredScolexTeratomaThe FallenThe Headless HorsemanMom's HeartIt Lives
Sisters VisThe Matriarch
Stage Corpse icon.png
ChimeraThe ScourgeRotgutMother
Chapter 5
Stage Sheol icon.pngStage Cathedral icon.png
Chapter 6
Stage Dark Room icon.pngStage The Chest icon.png
???The LambMega Satan
The Void
Stage The Void icon.png
Stage Home icon.png
DogmaThe BeastUltra DeathUltra FamineUltra PestilenceUltra War
Greed Mode
Ultra Greed
Ultra Greed
Ultra Greedier
The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth
Achievements Achievements Attributes Attributes Bosses Bosses TarotCard.png Cards and Runes Challenges Challenges Chapters Chapters
Characters Characters MainPageBabies.png Co-op Items Items Item pools Item pools Monsters Monsters Objects Objects
Pickups Pickups Pills Pills Rooms Rooms Seeds Seeds Transformations Transformations Trinkets Trinkets