Jacob and Esau are unlockable characters added in Antibirth. Both Jacob and Esau are controlled simultaneously, and they have separate items, trinkets, and health bars. If one of the two characters dies, the other will also die.
Both can hold active items: the active item key (SPACE) will use Jacob's item, and the card/pill use key (Q) will use Esau's item.
Jacob and Esau are unlocked by defeating The Witness for the first time.
- It is possible to take both items in double treasure rooms or boss room rewards with More Options by having Jacob and Esau each pick one up simultaneously.
- It is also possible to take 2 items from a Shop, even without the necessary amount of coins. Doing so will make Jacob and Esau's coins negative, but since the game cannot process having negative coins, they will become positive. For example, if Jacob and Esau have 27 coins and then purchase 2 items that are at full price (30 coins), their coins will turn to -3, then increase to 3.
- Key and Knife pieces are not shared between Jacob and Esau, so if the player intends to fight Mega Satan or enter the Corpse, you must pick up all the pieces with only one of the two brothers.
- Because cards, runes, and pills are used the moment they are picked up, the player cannot hold onto these for future use. The card Suicide King is hard-coded not to appear while playing this character.
- It is possible to only move Jacob when you hold the drop trinket and pill button (CTRL on PC/Right Trigger on default controller layout.)
- Both Jacob and Esau's speed will always be the same, and both will get changes to the speed stat.
- It seems that if Money = Power is picked up by one of the characters the damage will be updated only when the coins are picked up by the character with the Money = Power item (needs further testing)
- To enter a Challenge Room or Boss Challenge Room, both Jacob and Esau must meet the health requirements.
- Infamy can trigger on both Jacob and Esau regardless of who picked it up.
- Flight can make Jacob & Esau more challenging, as only the character who picks up the flight item will be able to pass over obstacles.
- If one of the brothers has Dead Cat, when Jacob & Esau die, they will respawn with one red heart each.
- When respawning as a different character, Jacob & Esau's items will merge onto a single character.
- This will not cause a Guppy transformation even if the brothers have three Guppy items between them.
- The three Knife Pieces will assemble the full knife if the pieces were previously divided between the brothers.
- If Esau had the Pony, this will grant the new character flight without taking up an active item slot.
- Using character reroll dice rooms will only affect the brother that stepped on them.
- When a bomb is used, both will place one bomb. They share the bomb counter, meaning that any bomb picked up is doubled.
- This allows saving one bomb on opening the Bedroom, the entrance to the Mines, and checking for secret rooms, or doubling the damage output.
- When one of the brothers picks a bomb upgrade, only his bombs are affected.
- The Exploded Firecracker will make the bomb of the holder explode before the other, pushing the second in the opposite direction. Without further planning, it can be dangerous.
- When one of the brothers receives damage, both will blink, even when the other is unharmed.
See Tips/Jacob & Esau.
- Rock Bottom - Complete the Boss Rush.
- Double Baby - Defeat Mom's Heart or It Lives on Hard.
- Red Stew - Defeat Satan.
- Damocles - Defeat The Lamb.
- Jacob's Ladder - Defeat Isaac.
- Birthright - Defeat ???.
- Magic Skin - Defeat The Witness.
Note that defeating Mega Satan does not unlock anything or give a completion mark.
- Jacob & Esau are the twin sons of Isaac from the Book of Genesis. Esau is described as being "red all over" when he was born, hence why his skin is red in this game. The reason why Esau has a sorrowful grimace may be of a story in Genesis where Esau was dying of hunger after an unsuccessful hunt, in which he asked Jacob to make him something to eat, but in return, Jacob wanted the heirloom blessing of his father, which had been bestowed upon Esau. Esau accepted the offering and regretted his choice afterward.
- If the player enters the seed "FART FACE" and selects Jacob and Esau, they will be reskinned into Green Pepper and Baggy Cap, two of _Kilburn's original characters.