The Lost

Character image

Health

No health

Stats

Damage

Tears

3.5 (*1.00)

+0

Shot Speed

Range

1

23.75

6.5

Speed

Luck

1.0

0

Starting Items

Pickups

Items

1 coin

Flight

Spectral tears

Unlock Method

It's complicated

Die in a

Sacrifice Room while holding

The Lost is a secret character in The Binding of Isaac: Rebirth.

The Lost starts with no health and cannot gain health by any means. Therefore, it will die from any hit.

The Lost starts with flight.

The Lost starts with flight, spectral tears, D4 (if unlocked) and Holy Mantle (after donating 879 coins to the Greed Machine).

The Lost starts with flight, spectral tears, Eternal D6 and the effect of Holy Mantle (after donating 879 coins to the Greed Machine) This form of Holy Mantle is inherent to the character rather than being a starting item, and as such will be present when switching to The Lost in the middle of the run through the use of Clicker, will not be present when switching away, and cannot be removed by any means.

The Lost can take devil deals and Black Market items for free.

Devil deals and Black Market items are presented as choices. Taking one will despawn all other deals in the room.
- Unlike other choices, devil deals cloned with Diplopia will not be a choice. All copies can be taken.

The Lost can activate the button in Greed mode without taking damage, for exchange of one coin less of the next wave's reward.

Notes

Many of the game's items provide no benefit to The Lost; for example, those that affect health or trigger on taking damage.
Resurrection items like Dead Cat will still work with The Lost.
Devil deals, while free, still count as making a deal with the devil and will prevent angel rooms from opening. Thus, a Credit Card is still recommended, or getting Chaos to acquire angel room items (except broken key pieces).
Isaac will be replaced by The Lost upon starting a third victory lap; however, Victory Laps do not allow the unlocking of achievements.
- Since the Lost's Holy Mantle isn't intrinsic, the Victory Lap Lost will always die from one hit unless the player has explicitly found the Holy Mantle.
If The Lost's Holy Mantle effect is lost while within a Curse room, closing the game, starting it up and then continuing the run will restore the Holy Mantle's charge, allowing The Lost to leave the room unharmed.
Using the D4 at all is not recommended as it will remove the Holy Mantle, making The Lost die in one hit.
The Lost's Holy Mantle effect is intrinsic to the character once unlocked, and it can't be rerolled.
The Lost starts with Eternal D6, even before it's unlocked.
Holy Mantle is intrinsic, but picking up another one does not double the effect.
- Being innate, this holy mantle effect is not shown in the HUD nor in the pause menu.
- It also cannot be re-rolled away.
  - Upon using the D4, the holy mantle effect will be temporarily lost. Leaving the room will regenerate the shield. (possibly a bug)

General Strategies

Main article: The Lost (Strategy)

Item Interactions

Birthright: Prevents items with the internal tag nolostbr from spawning. In practice, this automatically rerolls most items that aren't beneficial to The Lost, namely ones that only give health, flight, and/or spectral tears or activate upon taking damage.

Unlocking The Lost in Afterbirth

The Lost is unlocked by dying in a sacrifice room while holding Missing Poster.

Looking for Mom's Box in shops makes finding the poster easier.
Glitter Bombs, in conjunction with a large enough or infinite source of bombs (such as a Gold Bomb), have a small chance to drop trinkets, making it easier to find the poster.
- This method got nerfed, since Glitter Bombs now have a cap on drops per floor.
It is technically possible to unlock The Lost while holding Mysterious Paper, although the probability is small since it only has a 1/4 chance to imitate the Missing Poster. Dead Cat and other resurrection items could be useful for extra attempts.
- Since Divorce Papers always drop Mysterious Paper and have a cheap craft for Tainted Cain and his Bag of Crafting, a new possible method have been found where you spam runs getting the Divorce Papers early and dying in the first Sacrifice Room you can find. Even with the small chance of getting the unlock with Mysterious Paper, the high number of runs in a short period of time can be worth it.
Even while holding Missing Poster, if Isaac happens to teleport while taking the last heart of damage, you will die without unlocking The Lost.

Unlocking The Lost in Rebirth

The Lost is unlocked by dying consecutively with certain characters, with no other deaths. Deaths must be completed in the order shown here, and seeds can be used for the runs except for the last with Azazel:

Isaac must die to a Mulliboom in The Basement or The Cellar.
Magdalene must die to her own bomb in The Caves or The Catacombs.
Judas must die to any Mom attack in The Depths or Necropolis. Being killed by any monster spawned by Mom will spoil the entire attempt at unlocking The Lost.
Azazel must die to any Satan attack in Sheol. Being killed by The Fallen in the boss room or a Kamikaze Leech will spoil the entire attempt at unlocking The Lost. Being killed by using The Bible doesn't count as a Satan kill.

The Lost will be unlocked after dying to Satan's attack.

Notes on unlocking The Lost

Multiple lives (for example, obtained by Dead Cat) must be depleted before the intended death, as deaths while having extra lives do not count as a game loss.
Having any mods installed that triggers the mod flag will make The Lost unobtainable. To fix this problem, all mods have to be removed.
The game cannot be won as any character required to unlock it when unlocking it.
Champion versions of monsters and bosses will count for the death criteria.
Runs can always be safely reset.
Mom's Foot's stomp counts as explosive damage, which makes Pyromaniac a problematic choice when trying to complete Step 3.
Picking the wrong character while unlocking him doesn't mess up the unlocking process.^[1]
Quitting and Restarting the game in the middle of the unlocking process doesn't mess it up.^[2]
Picking up Lazarus' Rags, Judas' Shadow, or Ankh should be avoided. These items will revive the current character as a different one and therefore prevent the current unlock-step from being fulfilled.
Exploit: If you die during a required run, but hit the "start" button just as you die and reset before it shows the "Today I died" paper, it will not count as a death that spoils the run, instead it counts as a restart.

File Manipulation

By changing a file parameter, an unsuccessful try can be undone:

Backup the file Options.ini found in the Documents\My Games\Binding of Isaac Rebirth by making a copy of it in the same folder.
Open the original file with Notepad and change the SteamCloud parameter in it to 0. This will disable Steam Cloud gamesaves synchronization.
After an unsuccessful try, delete the original file and rename the backup copy with the name of the original file: Options.ini
Repeat steps 1 after each successful run until you unlock The Lost.
When finished, open the original file and restore the SteamCloud parameter in it to 1. This will enable Steam Cloud gamesaves synchronization again.

Helpful Seeds For Rebirth

Isaac

PC GPE3 2T1H (Must be on Normal difficulty. 2 Mullibooms south of starting point. Use the sacrifice room above to damage yourself first)

PC PS4 JTMD EZPF (Must be on Normal difficulty. One mulliboom directly below the starting. Go left first to get weakened)

PC GH9Y FSA8 (Hard difficulty, series of rooms containing mullibooms going down)

PC Q2V4 YZET (Hard difficulty, Cellar needs to be unlocked, 2x2 room full of mullibooms (about 6/7) when going up)

Vita GQHN NMKN (Go left, 4+ Mullibooms)

3DS 6Z2L AZ6J (Go left, 4+ Mullibooms)

3DS VNSM AHHG (Go up, weaken yourself at the spikes, then go up and die from the Mulliboom)

3DS PXRT XH49 (Go up, weaken yourself with the Frowning Gapers, then go down and die to the Mulliboom)

Maggy

PC ALFA 0NTS (Recommended Normal difficulty. Pyro in the first Treasure Room, adjacent to spawn)

PS4 FDRG 0CTE (Pyro in the first Treasure Room, adjacent to spawn)

Vita DXVW MQCF (Pyro in the first Treasure Room)

3DS YGDC T8SL (10 bombs in the first Treasure Room)

Judas

PC YR8E YXDV (Must be on Normal difficulty. Polyphemus in the first Treasure Room. Do not take devil deals, as Trinity Shield and Sacred Heart will be available in Angel Rooms. Keep the Book of Belial to ensure they show up. Also, from the pills from Mom's Coin Purse (1st boss, Duke of Flies), take the orange (Health Up) then the white one (Full Health), ignore the blue ones (Speed Down)).

PC N0G3 VLD4 (Both modes) - Dr. Fetus on floor 1, and Ipecac on floor 2.

PS4 DMTM NRD9 (Do not make a Devil Room deal in Basement II will spawn an Angel Room with Holy Grail in Caves I. Collecting everything grant huge tears.

3DS 180Y 7RDC (Lots of health early (Rosary in first Treasure room), good pickups (Mulligan is in second Treasure room, Dr. Fetus and Mr. Mega in the third and fourth). Skip the first Devil deal, as the Angel deals are Sacred Heart, Mitre, and Scapular. Remember to trigger scapular before entering the Mom fight if you take it, as the immediate foot stomp may leave you with the bonus soul heart.)

The Lost

PC HNA6 WEK7 (Dead Cat and Holy Mantle on first floor, helpful for practice runs)

Unlockable Achievements

The D100 - Complete the Boss Rush as The Lost.

-0- Baby - Defeat Mom's Heart on Hard mode as The Lost.

The Mind - Defeat Satan as The Lost.

Isaac's Heart - Defeat Isaac as The Lost.

The Soul - Defeat The Lamb as The Lost.

The Body - Defeat ??? as The Lost.

Zodiac - Defeat Ultra Greed as The Lost.

Dad's Lost Coin - Defeat Ultra Greedier as The Lost.

Sworn Protector - Defeat Hush as The Lost.

White Baby - Defeat Mega Satan as The Lost.

Holy Card - Defeat Delirium as The Lost.

Lost Soul - Defeat Mother as The Lost.

Hungry Soul - Defeat The Beast as The Lost.

The Baleful - Use Red Key (etc.) to open the hidden closet in Home as The Lost.

Godhead - Earn all 5 / 9 (except Ultra Greed) / 10 / 12 Completion Marks on Hard mode as The Lost.

Trivia

When The Lost's unlock requirements were discovered through the use of data mining, Edmund McMillen and Tyrone Rodriguez both expressed their disappointment, considering it impatient and "like swallowing a hundred dollar steak in one bite".^[3]
Right before the start of a run, some images appear to hint to unlocking The Lost, including the Missing Poster and The Lost itself.
Dying in a Sacrifice Room while holding the Missing Poster would yield a puzzle piece on Isaac's last will. These puzzle pieces, when put together, created the last wills of characters dying in the method used to unlock The Lost.
Before version 1.02, The Lost would die if a run was exited then continued.
When The Lost picks up an item, tarot card, or pill, you can see its arms that do not connect to its body.
Internally, The Lost has half a soul heart, which is hidden behind a permanent Curse of the Unknown-like effect. The singular soul heart is why The Lost can "pick up" soul hearts, black hearts, and eternal hearts. There are no ways to increase this health, though, as The Lost's health is constantly reset back to half a soul heart.
- Devil deals appear as requiring three soul hearts each as The Lost technically only has half of an invisible soul heart. This is cosmetic only, as devil deals are still free.
A loading screen (when Isaac dreams) depicts the "Voice of God" telling Isaac's Mom to kill her son as The Lost speaking to her from the attic.
The Lost's starting health is listed as "?" on the character selection screen.