The Binding of Isaac Wiki

For the bugs found in the base game, see The Binding of Isaac Bugs.

This is a list of all bugs currently found in Wrath of the Lamb, the expansion to The Binding of Isaac.

Please remove any fixed bugs/glitches, or edit them to correspond with the current patch.

The current version of WotL is v1.48. (1.50 for players with the Most Unholy Edition)


  • If you leave a Challenge Room or a Boss Challenge Room (By teleporting out or dying with an extra life), the challenge music won't stop until the point where it would loop.
    • Existed pre-DLC.
  • When fighting the first boss in an XL Depths/Necropolis, the music for Mom's battle will play, regardless of the fact that the boss is Mom or not. The same thing happens with the first boss before Mom's Heart in an XL The Womb/Utero.
  • On the Character Selection Screen, if you use Arrow Keys on the Keyboard to switch between characters, no clicking sound will be played.
  • Getting killed can cause the music for a room/floor to reset.
  • No sound effect for the Monstro's Tooth item.
  • If you die with no heart containers (Either as ??? normally or any other character who has 0 hearts due to the Devil Room), "Hereafter" doesn't play.
  • Getting Mom's Heart to 50% health causes Mom to say "Isaac!" Multiple times rapidly.
  • No sound for Gish's (Boss) shooting attack.
    • Existed pre-DLC.



  • Uh

    Secret rooms in XL dungeons can have regular rooms in them. The room above this has no doors.

    Using Mom's Pad against a Fat Fly may cause the fly to freeze and become invincible through the items duration, in which case can only receive damage by any other means except Isaac's tears.
  • Freezing an Eternal Fly with Mom's Contacts or Mom's Bra, and destroying the poop or monster it's orbiting while it's still frozen makes the fly permanently frozen until you leave the room (Unless you shoot it, which will move it into a corner).
  • As of 1.333, If you have Bob's Rotten Head as a Space-bar item, your chance of getting rewards by playing Fortune Telling Machines is greatly increased. Bob's Rotten Head may have replaced the role of Lucky Foot or Lucky Toe due to a bug in programming, or this may be intentional.
  • Having the Polaroid and at least one heart container lets you use Blood Donation Machines infinitely or until it blows up. Use all of your red hearts on the Blood Bank and for whatever reason, the Blood Bank heals half a red heart while you are invincible with the Polaroid.
  • Picking up The Joker Tarot Cards Card in The Chest may cause the game to freeze, then make you stuck in the item pick up frame while (most) of the items in the game scroll repeatedly above your head.
    • Happens with more items at more locations.
  • ??? dies if he only has an Eternal Heart.
  • Upon dying with Ankh and Dead Cat or 1-UP as any character other than ??? will result in you spawning as ???. Upon a second death, you will respawn with red hearts, but ???'s skin.
  • Playing as Eve does not result in the Whore Of Babylon being removed from the Item Pool, making it possible to get two of the Whore Of Babylon in the same playthrough. This does not have any effect.
  • Dr. Fetus combined with Mr. Mega causes no damage to Pride (or Super Pride); you must use normal bombs or your activated item in order to kill Pride at that point.
  • If you have an item such as The Candle or Notched Axe, pressing space and not using the said item in a room full of Pills, Tarot Cards, etc., you can pick up the Pills without stopping to show the "pickup" animation. (Confirmed)
  • Upon blowing up Goblins and/or Gazing Goblins, they will always go to the stunned/goo form. If they return to their normal form, they can walk through bombs instead of being held up by them. Thus, making Dr. Fetus a very easy way to get killed when fighting Goblins and Gazing Goblins. (v1.48)
  • If you try skipping the cutscene between levels in the same moment it starts, and the next level has the Curse Of The Labyrinth, all the rooms will be empty, and the Shop door will have the appearance of a boss room.
  • Previously, if you had an XL Depths/Necropolis floor, there was a bug/glitch that made you fight Mom first, and once you beat her, Isaac would crash.

Unlocking progress

  • If you unlock the Devil Room in The Womb/Utero 2 and travel to Sheol before unlocking ???, you will unlock the next two Endings automatically (e.g. If you have 5 ending so far, it will unlock 6 AND 7) as well as Ending 11 which it will play once you have defeated Satan, providing you do. If you fail to defeat Satan, you will be unable to unlock more endings by beating The Womb/Utero 2 on future playthroughs.
  • When Defeating Moms Heart for the first few times, in the secrets screen, it will show the latest secret (e.g. a noose) twice, side by side.
  • As of version 1.45, any process that erases so.sol (achievements fix, anti-virus or spyware software targeting so.sol, using Steam's Cloud storage), will result in 94/97 secrets being unlocked even if you had completed every unlock, including Platinum God (which now works again).
    • The four missing are as follows: Samson's Lock, Eve's Birds Foot, the Left Hand, and Cain's Eye. Eve's and ???'s in-game secrets are still reversed. So, if you had everything else from before, don't waste your time trying an Eve run again; play with ??? instead to unlock Eve's Birds Foot.
      • These 4 secrets will now stay unlocked as long as so.sol isn't erased.
    • Do NOT attempt to play the game on multiple computers using the same save file via Steam's cloud saving. The above 4 secrets will get erased if doing so and will need to be unlocked AGAIN. Unless the save files were backed up previously, ALL your computers will have the above 4 missing again.
    • Make sure your anti-virus or anti-spyware software leaves so.sol alone.
    • Be prepared to get these 4 achievements again if using the achievements fix of erasing so.sol.
  • Beating the Chest with Cain, Judas, Eve, ??? and Samson causes the incorrect achievement to unlock on Steam. Isaac and Maggy's achievements unlock correctly.
    • In-game achievement unlocks may randomly disappear.
  • Having Depths XL and killing the first boss before entering the Item rooms give you Samson, after that you still can get the items from the item rooms and then kill Mom.
    • The problem here is that for the XL levels, the first boss is also "tagged" the same as Mom. This means that for any clear conditions, only the first boss needs to be killed.
  • Sometimes, when unlocking secrets/achievements, no notification will pop up during the gameplay. The number in the collections will increase however there will be no picture showing the unlock
    • This happens even without the Wrath of the Lamb expansion.
    • If this bug happens early enough, it will result in things like Ending Cinematics, or the 10th challenge not being unlocked when you otherwise would have gotten the notification.
    • If playing the Steam version, exiting and re-entering the game may award the missing steam achievements. However, there will still be no in-game pop-up informing you of the secrets unlocked.
    • Even though no pop up will be shown, the item can still be obtained normally (ie. Even if no pop up is shown for Blood Rights, it can still be found.)
    • This can be fixed by deleting FlashAchievements.exe, going to your Steam library, right-clicking on The Binding Of Isaac, clicking on Properties, and then clicking on "Verify Integrity Of Game Cache". This will give you the achievements upon starting up The Binding Of Isaac.
  • The Counter for the Secrets goes up and you can find the unlocked secrets in-game, but you don't get Pop-ups for the Unlock, nor can view them in the Stats.
    • In some cases, the secrets counter fails to increment and secret unlock pop-ups fail to display, but the items are still unlocked.
  • When doing a challenge, dying with Ankh and turning into ??? makes the challenge impossible and allows you to continue to Sheol/Cathedral after killing Mom.
  • Secrets unlocked after beating Mom/Mom's Heart/etc. for cutscenes unlock during the cutscene, so only the sound is heard. After unlock, they won't pop up at the menu like usual, but they will show in the secrets section.
  • Killing Ultra Pride will always give you the pop up for the Left Hand trinket, regardless of the fact that you already unlocked it or not.
  • When you unlock Cain's Eye, a duplicate Cain's Eye page replaces the "You unlocked Magdalene" page in the found secrets. This fixes itself after the game is closed and reopened.
Bidning of isaac glitch

I got hit into this middle of a room by a spider...



Stuck on The Chest after using Telepills (Room with no exits or bombable walls)

  • BoI Bug

    Example of being trapped in an isolated area around the Secret Room by teleporting.

    Teleporting to the I AM ERROR room while in the chest forces you to quit. (Empty room with no exits.)
  • Using The Moon Tarot Card may force you to exit the secret room to an isolated area with no doors. This can also happen when teleporting to a random room with Telepills (found when under the labyrinth curse).
  • Also, secret rooms in XL levels can be naturally connected to isolated rooms. You can go from the secret room to the isolated room (with a bomb), but can't go back if you don't have any bomb left. You just get stuck.
  • In the Arcade room, you can re-enter it multiple times to change the slot machine to a Fortune Telling machine as long as there's a fly in the room.
  • Exiting the Curse room while flying deals damage unlike entering it while flying. This may be intentional.
  • v1.3 - In The Chest, if you teleport into the Secret Room and are unable to blow up the Secret Room entrance you may be unable to escape, ending your run. More information on The Chest page.
  • Pausing right after picking up the treasure in a Challenge Room/Boss Challenge Room will spawn all waves of enemies at once.
  • In 1.48, if you kill Isaac with the Polaroid, you can walk into the chest to enter the Chest world. If you tag the chest (beginning the fade to white) and then run out of the room, the graphics change to the Chest but you remain stuck on the Cathedral, thus making it impossible to complete the run.
  • 1.48 - If you spawn a regular fly with the Slot Machine or Portable Slot Machine, leave the room, and come back, the room will have reset.[1[2]


  • When entering a room with any kind of Boils in it, they will spawn at their full size and go back to their small size right after.
  • Whenever there are Clots in a room, all enemy projectiles will flash black like Clot's.
  • Spiders are not blocked by bombs and moving bombs (pushed or Fetus in a Jar) pass through them.
  • B. Lickers can sometimes get stuck in a wall and become unkillable without spectral shots or wide-range bombs, possibly forcing a reset if the player cannot bomb or teleport out.
  • Enemies can get stuck in doorways.
  • Ground-bound enemies that can move diagonally (including Keepers) will sometimes "squeeze" through a corner created by two obstacles (pits or rocks), even though they can't normally travel over them.
  • The Larry Jr.s spawned in the Boss Challenge Room have two overlapping segments.
  • Brains can sometimes become stationary once they reach a wall, pit, or rock.
  • When using Mom's Bra while fighting a blue champion Gurdy Jr as a boss (two Gurdy Jrs at once), and killing one of them before the end of the effect, the remaining Gurdy Jr will appear to flashing at the corners of the room, while actualy he is simply moving really fast through the room (so fast it doesn't damage you) . it will come back to normal after a while.


  • Attacking Mom's Heart/It Lives! with the candle while it is hiding damages it. When it is left with a quarter of it's health left, it will not come down until you defeat all other enemies in the room.
  • If you kill a boss, take the reward, and then kill yourself with Dead Cat, you will respawn outside the Boss Room, and you can fight the boss a second time. The trapdoor will still be there, you can get a second reward, and the boss can also turn into a Champion version.
    • Existed pre-DLC.
  • Killing Mom or Satan while under the shadow of their foot will cause you to take 1 heart of damage.
  • On an XL floor, if you defeat a normal boss, don't pick up the item, and proceed to fight one of the Four Horsemen as a second boss, returning to the first boss room and re-rolling the first boss's item will always result in a second Cube of Meat.
  • Issac killed by nothing

    Killed by nothing

    In some rare cases in a boss fight you can lose all your hearts and instantly die with a kill screen with nothing on it.
  • "The Fallen" Boss tends to be stuck within his Chasing Charge Attack. Planting Bombs on his way and damaging him with those Bombs unsticks him.
  • Fighting any boss and having Cursed Skull and then killing them right when you're down to a half-heart will result in no trap door appearing.
  • Sometimes Larry Jr. will get stuck behind his poop rather than eating through it.
  • Larry Jr. can sometimes spawn poop in walls or rocks.
  • When Pin goes underground after burrowing or firing an Ipecac shot, you can still damage him.
  • Using The Candle against War when he is using his attack in the air to randomly drop troll bombs will damage him. If his health reaches half in mid-air, he will not return to the screen and the player will be stuck.
    • It may still be possible to damage him with the candle, even if he isn't on the screen. Just look out for a spot where you can see his life decrease when you shoot the candle.
    • Also happens when War is poisoned.
  • Sometimes, one or both pieces left after Envy splits are those of Super Envy; they are blue, will split into three if they're big enough, and can drop Forever Alone if killed last. (This may not be a bug.)
  • Killing Mom's Heart with The Bible immediately after going into the room kills the heart, but the boss health label stays stuck on the HUD.

    Glitched health bar after killing Mom's Heart.

  • Pestilence will always fire two ipecac shots at Isaac upon entering the room, with no animation playing.
  • Brimstone charges normally in any room that has no enemies, but in battle it releases small squirts that deal about 45% of it's original damage.
    • This is due to the player pressing fire too quickly. If you press fire before the brimstone animation finishes, you will cancel it, rendering any cancelled animation frames completely damageless.
  • During the Satan fight, Satan's statue may act as a Tinted Rock (has a chance to spawn soul hearts/keys/bombs/golden chests when damaged by an explosion.) It is also possible to be forced to exit the room when hit by his third form near the door.
  • When the Green Champion version of Larry Jr. fires a shot upwards, his head turns into an upward-facing segment of The Hollow. Similarly, fighting a Green Champion version of The Hollow when he fires sideways will turn his head into Larry Jr.'s.
  • If you kill Satan while using Moms Pad, the game will become stuck, making winning impossible
  • When in a room with two horsemen of the apocalypse that charge, i.e. War and Famine in the Cathedral level, one can push the other completely out of the room temporarily, however the horseman that was pushed will go back into the room moments after


  • In Challenge #10 "The Purist", if you find an Error Room or use We Need To Go Deeper in The Womb/Utero II or XL, you can enter She
    Conquest War Glitch

    The Conquest/War Glitch in Necropolis I.

    ol instead of the Cathedral. If this happens, killing Satan will count as clearing the challenge.
  • (Only in WOTL DLC as of v1.48) On rare occassions, in Challenges #3 "Large Marge" and #9 "Isaac Was Good Today", if you pass into the room, Depths I, before entering, you will go through the usual transition from room to room. TBOI will be black for about 15-60 seconds. Then, the room transition will go through again. But only this time, in black and white, and with nothing going on in Isaac's thinking bubble. Afterwards, (about 10 seconds) the same thing will happen. Then you will go into Depths I. Afterwards, gameplay is normal.
  • After defeating It Lives! for the second time on a run of challenge #6 The Doctor's Revenge, a chest may appear instead of the beam of light to the Cathedral. However, the trapdoor to Sheol will still appear along with it. Entering this chest doesn't go to the Cathedral, but instead skips to the credits, with no special ending before it. This does not occur when completing a run without playing said challenge.
  • In challenges 1, 2, 3 and 4, where you can only go to the depths, if you get an I AM ERROR room or use the "We Need To Go Deeper" in Depths 2, you go down to the next floor and the game crashes or freezes for a very long time.


  • Using a Forget Me Now in the Large Marge challenge does strange things. (It regenerates the level, but with a new graphical set - this leads to strange things like facing Mom in the Womb and Mom's Heart in Sheol)
    • Bosses will be as if the level had been regenerated normally, but the graphical set and in-between levels will act as though you were one stage deeper. Monsters may appear by either parameter. For example, a level that should be the Depths will have the appearance of the Womb, but monsters from either level may appear.
    • This bug appears to make the challenge unwinnable; Mom appears in the first of the two boss rooms rather than the second, and when defeated the four doors explode as normal, but the challenge does not register as cleared, leaving you trapped unless you have a teleportation item. Using it may allow you to proceed to the next boss room, but this remains untested.
  • Stats window can sometimes glitch out and show false stats if equipped with the DLC. Typically this manifests as not acknowledging the effect of upgrades.
  • Issac Glitch

    An example of the glitched Issac that spawns with The Rock.

    The info plate that displays on the bottom right corner every time you pick up an object sometimes doesn't display or just the half of it is displayed.
  • In the second Necropolis and Utero stages, sometimes the lower left corner of the screen that displays the stage name doesn't have a number (or it doesn't display "XL" if Curse of the Labyrinth is activated).
  • The Mask of Infamy has no health bar. Edmund McMillen has stated that this is intentional because "the thing inside the mask is not living", but it may actually be due to technical limitations (i.e. Requiring a second health bar for the mask, which would call for a lot of unnecessary recoding).
  • TNT barrels, rocks, and poop sometimes appear inside of walls.
    Tnt wall
  • Trinkets have the same icon on the map as tarot cards. (Intentional?)
  • Even if the Devil Room in the boss room for Mom's Heart/It Lives is replaced with an Angel Room, it will still contain a trapdoor to Sheol.

    The tarot card-trinket bug

  • When shooting a fully charged Chocolate Milk shot while facing sideways, Cain's eyepatch will move to a different part of his face, then move back to its original place.
  • ??? has color mismatch issues with items such as the Holy Grail much like he has with the Growth Hormones.
  • Maggy is named "Magdalene" on the Character Selection Screen, but when you encounter Mini-Bosses, it says "Magdalena" instead. (Example: Magdalena vs. Gluttony)
    • Existed pre-DLC.
  • When the Tarot card 'The Devil' is used on War, his body turns invisible, and he cannot be seen. He still attacks the player.
  • Getting Kamikaze! while having the Holy Grail turns the flying animation into a normal walking animation, although you still can fly.
  • When entering different rooms during the Curse of Darkness, the map will briefly show a heart and revert back.
  • If the Red Patch is activated with a flying item other than Transcendence, said flying item's visual effect is not visible and Isaac apears as a floating head.
  • Killing Scolex with bombs, IPECAC or other explosive attacks can cause the explosion animation to loop in place for an indefinite period of time. (Existed pre-DLC as well.)
  • Upon acquiring certain familiars that drop Pick Ups (Sack Of Pennies, Little C.H.A.D., etc.), Brother Bobby will appear. He will disappear when you exit the room.
  • Some familiars can replace others with Brother Bobby unless Brother Bobby is actually found (permanent) or the Holy Water that caused the change is spilled (temporary).
  • When entering in a new floor, if the secret room is adjacent to the spawn room, it will appear briefly then disappear.
  • When picking up Tear increasing items, the tear stat (and range stats occassionally) do not visibly increase, and on rarer occasions, do not increase the stat at all
    • Sometimes, stat-boosting items appear to increase the "wrong" stat, e.g. the Pentagram resulting in a Tears upgrade. This may or may not be true in actual gameplay.
  • The health bar found when fighting War and Famine simultaneously (in The Chest) only tracks War's health.
  • Ending12 Glitch

    The chest from Ending 12 in the Jet-Black "corner"

  • If Scolex fires a bomb that collides with a poison tear (and maybe with other kinds of tears), it is frozen in mid-explosion and becomes harmless. The "cloud" it leaves behind can be pushed around like a regular bomb.
  • In the credits, Sloth still has the same appearance as a Globin; he's red instead of green. (This is the case even without the DLC, and it may be a joke related to Sloth's "lazy" design.)
  • While fighting Pin, he may randomly regain all of his health. The layer of ground he creates when burrowing will disappear, however.
  • During Ending 12, when it shows the chest in the corner, the walls may be completely black.
  • Sometimes, when a blood beam (like the one a vis shoots) is on screen, Robo-Baby fires a laser similar to the lasers fired when Polyphemus is collected with Technology. This does not deal increased damage.
  • Super Sloth is bugged as of V 1.48, and he has the head of a Globin instead of a Gazing Globin.
  • When exiting to title screen from basement, following graphical error might happen. 

    The Binding of Isaac - Werid Bug (NOT EDITED)

    Graphical error


  • Technology 2 + Brimstone has a small graphical glitch when used together, and there's no sound effect for

    Brimstone + Technology 2 glitch

    Technology 2.
    (The sound bug happens even without Brimstone.) (In combination with some other items like Brimstone, Bloody Lust and others may cause Brimstone to be bugged, preventing it from being fired but dealing mass damage, killing It Lives in about three seconds. Picture below.)
  • Technology 2 + Mom's Knife: Technology 2's laser fires as normal but does no damage.
  • Technology 2 + Epic Fetus: Technology 2's laser fires briefly, before the bomb crosshair starts flashing. The laser does normal damage. The crosshair is also being delayed a bit before it appears.
  • Acquiring IPECAC first, and then Technology 2 will give you both attacks. The reverse will max your attack stat, but will not yield the IPECAC attack.
  • Shots don't penetrate rocks when using Technology 2 and Ouija Board, unless paired with Technology 1.
  • Cannot throw Bob's Rotten Head when equipped with Technology 2.
  • Technology 2 + Number One (Cain only): Still doesn't fire Number One tears, even though they come from the lower part of his body.
  • The Candle will not fire with Technology 2.
  • When using the 3 Dollar Bill in conjunction with another tear effect, there is a chance the 3 Dollar Bill will override the other effect instead of complementing it.
  • The Rainbow Baby might get buggy and gets replaced by Brother Bobby through a fight, but switches back after it.
  • When collecting a Harlequin Baby while holding a Rainbow Baby, the Rainbow Baby will become a second Harlequin Baby
  • Holy Water may cause the next tear-firing familiar in line to revert to Brother Bobby until the Holy Water effect is activated.
  • If you manage to obtain, Isaac's Head, Ghost Baby and Little Steve, then you may find that you end up with two Ghost Babies.
  • Having Robo Baby and Little Steve causes Little Steve's shots not to fire and show random purple splotches on the walls in random directions (as if Little Steve shot there) during a fight, but after he shoots normally.
  • Isaac7

    Two Abel familiars

    If you obtain Isaac's Head, Little Steve, Abel, and then Sister Maggy familiars, Little Steve will turn into a second Abel.
  • The blue flies created from using Guppy's Head sometimes glitch out and get stuck in one place, and the animation stops.
  • Sacred Heart's description says "Space to Use" but isn't a use item and doesn't replace your current use item.
  • If you acquire Brimstone after picking up Technology 1 and then Ipecac you will be completely unable to fire no matter how long you charge Brimstone. (May be the same as the bug listed below).

  • Guppy's Tail is supposedly unlocked by completing the 9 Deaths challenge, but it is possible to find it before completing the challenge.
  • Doctor's Remote and Epic Fetus' targets can bounce off fires, and a burning sound will play.
  • Mouse-listener lags the Player Input severely when used with Doctor's Remote/Epic Fetus.
  • IPECAC does not interact correctly with Spectral Tears, regardless of whether you gain them before or after IPECAC. (e.g. if you are flying above a rock, shooting will blow it up in your face, damaging you)
  • Liberty cap can give the compass effect temporarily.
    • Might be intentional.
  • With Epic Fetus in a Jar and Technology, the laser will fire but will not be visible.
  • Sometimes, Dr. Fetus bomb's hitbox doesn't work and goes through enemies.
  • Sometimes you may acquire bugged pills which end up being different color upon use rather than what it is being displayed to you.
  • After using Mom's Bra, the Epic Fetus crosshair will be frozen as well. Bomb's will still drop onto the crosshair normally.
  • Picking up Mom's Knife when you already have Epic Fetus results in Mom's Knife working only in the room you picked it up in, reverting back to Epic Fetus once you leave.
  • When picking up the Treasure Map or The Compass item, the minimap does not update until you exit the shop/room you found it in.
  • When an enemy with an Eternal Fly is killed while frozen, the fly does not turn into a large Attack Fly.
  • Laser-type hits on a deployed Best Friend can kill you instantly, even when the attacks don't hit your character. The death sequence itself is also glitched out in several ways - Best Friend shakes for a while, and then the standard death screen pops up, with Isaac as the cause of death. The rest of the screen doesn't dim out either.
  • If you have both Abel and Dead Cat, the floating cat head will move with Abel instead of following Isaac.
  • The <3 item does not show its name on the collection screen when selected.
  • Some items in the Angel Room will appear without being unlocked. (ex. Guardian Angel without having beaten Satan with Maggy)
  • Dead Sea Scrolls can possibly select Wiggle Worm, which is not an activated item. It has no effect when this occurs.
  • More than one copy of a trinket may appear; however, it is impossible to pick up the second copy whilst holding the first, even if you have obtained Mom's Purse.
  • Using a Forget Me Now on the Cathedral will take you to Sheol.
  • Using The Candle while having Mom's Knife will let the knife float in midair allowing Isaac to move away until he throws the flame. The knife can also float outside the screen sometimes but will come back.
  • 9 Volt sometimes may not function with Bob's Rotten Head.

    Whore of Babylon Ankh Bug

  • After dying and becoming ??? (Due to the Ankh), if you aquire Dead Cat and die again you will be spawned with 1 regular heart, but the game will still recognize you as ??? and all achievments unlocked will be unlocked under ???.
  • Hugging a wall and activating Kamikaze! will not damage Isaac.
  • Using the Razor Blade while having one or an half heart will show no image on Isaac's Last Will.


  • If you just run the .exe file for BOI, sometimes you can unlock the Golden God achievement without earning it.
  • After beating Isaac, it is possible that the title screen doesn't show a piece of The Polaroid.
  • If navigating the Secrets menu with the keyboard, each key press will be counted twice. Using the mouse to navigate works as intended.
  • If you drop down to a floor with a room that requires a key (Shop, Treasure Room) south from you, it will force you to use a key to unlock it.
  • Rarely, validating the Steam files will delete all of your progress and statistics.
  • White cutscene
    Challenge Rooms will sometimes not open, even if at full health.
  • Sometimes, when you try and skip the dream sequence between floors with the Spacebar, the game freezes, the screen turns black, then plays the cutscene, but the thought bubble has no animation in it and the colours turn white and pale pink. Usually happens in the cutscene before Depths 1, and on the Womb cutscenes. Sometimes doesn't carry on with the no animation white and pale pink colour but simply turns off by itself.
    • This whited-out-cutscene-freeze happens quite reliably when (1) generating an XL level (i.e. Challenge 3) AND (2) holding an Eternal Heart piece during the level transition.
  • Skipping the dream sequence is dangerous in general - it sometimes can freeze your game, to the point it will never unfreeze, and you will have to close the game with Task Manager, ending your current run and possibly losing some progress (as TBoI saves it strangely).
  • You can't skip Ending 13 or the Epilogue.
  • Having the game in a small window setting will cause item pick-ups to not have phrases (after picking up an item, there will be a blank description box of the item) (Possibly not a bug)
  • Making deals with the devil can sometimes take all your life, but you are not dead.
    How is that supposed to work.

    Making deals with the devil can result in having no life left, but still be alive.

    (exact conditions unknown, it is also unknown if this bug existed pre-DLC)
  • In Wrath of the lamb, when the screen fades to black, the player can press escape, space, then the left or right arrow keys, in rapid succession, to select a locked character and then play as that character. Using this glitch can result in using a character to unlock that character in a run.