| Base Health|
| Base Damage||3.5|
| Base Fire Rate||1|
| Base Range||23.75|
| Base Speed||1|
| Base Shot Speed||1|
| Base Luck||0|
|“||To prove your love and devotion, I require a sacrifice. Your son, Isaac, will be this sacrifice. Go into his room and end his life, as an offering to Me to prove you love Me above all else.||”|
— The Voice from Above, Introduction
Isaac is the main and titular character of The Binding of Isaac and The Binding of Isaac: Rebirth.
He is the default and only character a new player can select to play as and is a fairly basic character with balanced stats. Isaac does not start with any initial Items until The D6 is unlocked and instead starts with one bomb and three full heart containers.
Narrated by Matthias Bossi
Isaac and his mother lived alone in a small house on a hill. Isaac kept to himself - drawing pictures and playing with his toys as his mom watched Christian broadcasts on the television. Life was simple and they were both happy. That was, until the day Isaac's mom heard a voice from above. "Your son has become corrupted by sin. He needs to be saved." "I will do my best to save him, my Lord," Isaac's mother replied, rushing into Isaac's room, removing all that was evil from his life.
Again, the voice called to her. "Isaac's soul is still corrupt. He needs to be cut off from all that is evil in this world and confess his sins." "I will follow your instructions, Lord. I have faith in Thee," Isaac's mother replied, as she locked Isaac in his room away from the evils of the world.
One last time, Isaac's mom heard the voice of God calling to her. "You've done as I've asked, but I still question your devotion to Me. To prove your faith, I will ask one more thing of you." "Yes, Lord. Anything," Isaac's mother begged. "To prove your love and devotion, I require a sacrifice. Your son, Isaac, will be this sacrifice. Go into his room and end his life, as an offering to Me to prove you love Me above all else." "Yes, Lord," she replied, grabbing a butcher's knife from the kitchen.
Isaac, watching through a crack in his door, trembled in fear. Scrambling around his room to find a hiding place, he noticed a trap door to the basement, hidden under his rug. Without hesitation, he flung open the hatch, just as his mother burst through his door, and threw himself down into the unknown depths below.
|Isaac's Head||Complete Boss Rush as Isaac.|
|Lost Baby||Defeat Mom's Heart or It Lives as Isaac on Hard Mode.|
|Mom's Knife||Defeat Satan as Isaac.|
|Isaac's Tears||Defeat Isaac as Isaac.]]|
|Missing Poster||Defeat The Lamb as Isaac.|
|D20||Defeat Blue Baby as Isaac.|
|Lil' Chest||Defeat Ultra Greed as Isaac.|
|Fart Baby||Defeat Hush as Isaac.|
|Cry Baby||Defeat Mega Satan as Isaac.|
|Buddy Baby||Earn all Hard Mode completion marks.|
- Isaac, both the character and the game itself, is a reference to the biblical story The Binding of Isaac, in which Abraham attempts to sacrifice his son, Isaac, to God in order to prove his loyalty to Him. Abraham does so as he is instructed by God, only to be told just before the sacrifice that it was a test and that he should not actually kill his son.
- Isaac's mother possibly shaved his head, for God instructed her to cut him off from evil.
- This can possibly be proven false by observing the pictures in the Ending 14, in which Isaac can be seen in multiple pictures with his father, supposedly before Mom heard the voice from above. In these images, Isaac is bald.
- It is also possible that she removed his clothes because they were considered evil and sinful.
- It is also possible that Isaac was castrated, for we do not see his genitals, despite him being naked.
- This, however, may just be censoring on Ed's part.