- For the bugs found in the Wrath of the Lamb expansion, see Wrath of the Lamb Bugs. Do not add bugs related to Wrath of the Lamb content in this page.
This is a list of all bugs currently found in The Binding of Isaac.
- When selecting a character, it will 'hover' on Isaac by default, pressing spacebar starts the game, as the screen fades you can select other characters by pressing the following keys in quick succession: Escape, Spacebar, Left/Right depending on which character you wish to be, for example, pressing right twice will select Cain. If done before the screen completely fades to black, you will be whatever character you choose. This is particularly useful for new players who don't want to use Isaac by default.
- In the Collection, the item <3 only shows the picture on the right, not the title. (This may be intentional)
- The game may not respond for a bit, (when you go into a trapdoor and you're about to enter a level) and then the brightness becomes very high. (Happens much more frequently with Wrath Of The Lamb DLC)
- Pressing the arrow-keys in any direction while leaving a room will freeze Isaac's head in that direction until another directional key is pressed.
- The item Whore Of Babylon does not get removed from the item pool even if you start as Eve, making it possible to get two Whore Of Babylon items in the same playthrough. This does not have any special effect.
- A monster can squeeze a player between the corners of non-accessible tiles (like pits) and the player will not be able to get back out unless they have bombs or a flying/hovering ability. You are now trapped and must restart the game.
- If you have extra lives due to Dead Cat or 1-up!, killing a boss and then killing Isaac (With a Bomb, Razor Blade, etc.) before picking up the item will cause the boss to respawn (Possibly in their Champion form) and will allow you to get another item.
- It appears that, if you have a 1-Up while fighting Scolex, or other conflicting items, it is possible for your game to lock up, and stay at the spotlight animation after death.
- This happens with or without extra life items.
- When fighting any jumping bosses, such as Monstro and Blastocyst, using Mom's Bra causes them to become stuck in the air and float away, unable to be damaged until the Bra's duration ends. Furthermore, if Mom's Pad is used against Chub/Larry Jr. and you are in a position where you meet the lines separating their segments, they will split apart and run away from you in opposite ways, but they will reconnect when the duration ends.
- When killing Mom, the screen turns red for a second. If any item that can cause Isaac to teleport is used, the screen will remain red until the game is shut down. This bug also persists through the title screen, but it fixes itself once the player selects a character.
- When you are fighting Scolex and he shoots three IPECAC shots, the explosion animation may get stuck on the floor, turning into an object and can be pushed by player. This rarely occurs. In extremely rare happenings this can happen in a Pestilence fight.
- When you kill Satan with Mom's Knife, continuous amounts of blood will appear. Satan's statue will also appear. This may also occur naturally on rare occasions.
- Dealing poison damage to War via items that cause poison damage (Such as The Common Cold) while off screen causes him to get stuck in the walls, making it impossible to complete the fight.
- If you enter a challenge room, open the chest or take the item, and pause right away, you will hear 3 monster spawning sounds. Now unpause, and all 3 waves spawn at once. This can also happen if you get an Achievement pop-up (such as the Common Cold) as a result of the item you pick up to start the challenge. If you pause the game for a shorter time (for example, by using The Necronomicon, as its animation pauses the game), you may get the second wave spawning before first one is killed.
- At least in Challenge rooms, you can get knocked through walls and closed doors by Monstro. If you are knocked through a door, you'll just end up outside, but if you are knocked through a wall your game will be screwed.
- The Pooters in Basement's challenge room spawn right after the Red Flies, instead of waiting until they die. This effect occurs without use of the pause glitch.
- Might be intentional.
- Various familiars will temporarily turn into Brother Bobby when you collect another familiar, this effect lasts until you leave the current room.
- Having Sister Maggy, Little Steve or Robo-Baby and then obtaining a 1-UP will cause this.
- Having Little Steve, Little Gish or Demon Baby and then obtaining Little C.H.A.D. will cause this.
- Having Sister Maggy, Little Steve, Little Gish or Robo-Baby and then obtaining The Relic will cause this.
- Having Little Steve and then obtaining Sack Of Pennies will cause this.
- Having Robo-Baby and then obtaining Bomb Bag will cause this.
- Having Little Steve and Brother Bobby and then obtaining Little Gish will make Brother Bobby disappear.
- If you have Bob's Rotten Head and are in a room with another activated item, pressing spacebar to hold Bob's Rotten Head above Isaac's head, and then picking up the activated item will cause Bob's Rotten Head to appear over Isaac's head and on the pedestal at the same time. Throwing the head will use up the item's charge. You can then pick up Bob's Rotten Head again, and it will be fully charged. This trick works even when usable item is already out of energy, meaning that in some cases (such as Challenge Rooms) you can use Bob's Rotten Head infinitely.
- Due to very bad interaction with Brimstone and Bob's Rotten Head, if you use the Rotten Head while you have Brimstone, you will not be able to charge and shoot Brimstone, drop bombs, and/or use your Q item.
- When using The Gamekid with Technology, the controls will be inverted for the left and right directional keys until you leave the room.
- The Razor Blade shows no picture on Isaac's Last Will.
- If you have an item that gives you flight (such as Lord Of The Pit) and Kamikaze!, Isaac will not be flying, but he can still pass over obstacles such as Rocks.
- When you go into a mini-boss fight and you have an item that gives you flying abilities you are actually able to blow up the door and fly out. (Tested with all flying and bomb items) Note: The door visualy doesent break but it behaves as a broken door.
- When using the High Priestess tarot card in a room where there is only one enemy (for example, a boss), using a spacebar item with a cinematic (like the Book of Belial) immediatly as the foot stomps may cause it to stomp twice instead.