How to Unlock Jacob & Esau in The Binding of Isaac (Repentance)

Jacob & Esau are the only duo character in The Binding of Isaac, added with the Repentance expansion. They are not available when you first install the DLC. You have to earn them by reaching and beating one specific boss deep inside the alternate path that Repentance introduced.

Quick answer: Defeat the Mother boss at the end of Corpse II with any character. When the credits roll, Jacob & Esau are unlocked and selectable at the character menu.

Jacob and Esau in The Binding of Isaac — Image: Nicalis

What you need before you start

The unlock requires the Repentance DLC. Mother is the boss at the end of the Corpse floor, and she is not the same fight as Mom, Mom’s Heart, or It Lives. Reaching her means assembling the full Knife from two hidden pieces, opening the alternate ending path, and clearing Corpse.

You can complete the whole run with any character. There is no specific character requirement for the unlock itself.

Get the first Knife Piece in Downpour II

Take the alternate path to Downpour and reach Downpour II (or its Dross variant). Clear the floor’s rooms so you can move freely.

Find the room with a Mirror and locate the white/blue-grey fire on the same floor. Walk into the fire and let it damage you. This turns you into The Lost and leaves your body behind.

As The Lost, enter the Mirror to reach the inverted mirror world. Head to the item room on the other side, clear the re-spawned enemies, and pick up Knife Piece 1. You can step back through the Mirror to return to normal afterward.

Get the second Knife Piece in Mines II

Reach Mines II (or its Ashpit variant). Search every room for three yellow buttons and press all three. Pressing the last one completes the minecart track.

Find the minecart on the floor and ride it into the new area. Knife Piece 2 is here.

The moment you grab the piece, a large enemy spawns and chases you. It will not stop until you reach the room where you boarded the minecart, and it can kill you in one hit. Use bombs to clear blocked routes and escape.

Note: Flight makes the chase far easier, since you can ignore most obstacles while running back.

Open the red door and clear Corpse

With both pieces collected, the full Knife forms. Take it to the end of Mausoleum II and defeat the boss there. A red door appears, which you open by firing the Knife at it.

Go through the red door and beat the boss waiting beyond it. Then exit the room and drop through the hole to reach Corpse, the new Repentance floor.

Clear through to the end of Corpse II and defeat Mother. Winning this fight rolls the credits.

How to confirm the unlock worked

After the credits finish, the game shows that Jacob & Esau are unlocked. They become selectable on the character menu. You will also see that a Strange Door has appeared in the Depths, which is a separate progression path you can explore later.

How Jacob & Esau work once unlocked

The two are treated as a single character but exist as separate bodies. They share coins, bombs, and keys, and move at the same speed, but keep independent stats, items, and health. Both have collision and can drift apart if you bump into objects. Holding the Drop button pins Esau in place so you can reposition Jacob freely.

If either Jacob or Esau dies, both die and the run ends, no matter how much health the other has. Because of this, defensive play matters more than with a single character.

Stat	Jacob	Esau
Health	3 red hearts	1 red heart + 1 soul heart
Damage	2.75	3.75
Tears	+0.277	-0.1
Shot speed	1.15	0.85
Range	5.00	8.00
Speed	1.0	1.0
Luck	1.00	-1.00

Esau hits harder but is more fragile, so investing in extra health for him keeps the duo alive longer. A few mechanics are worth knowing right away. Speed changes are only half as effective but apply to both. Placing a bomb makes both characters drop one while consuming only a single bomb, so aligning them can open barricaded doors cheaply. Their combined Luck starts at 0 for room clear drops, since 1.00 and -1.00 cancel out.

The early unlocks you can earn while playing as them, such as Birthright, are strong for future runs, which makes the duo worth sticking with despite the steeper learning curve.