Obstacles

Obstacles are objects that will get in Isaac's way in rooms.

= Indestructible Objects =

Metal Blocks

 * Blocks movement and projectiles.
 * An explosion's blast radius will not extend past it.
 * Cannot be destroyed or removed.
 * Can be re-rolled by the D12 into a destructible obstacle.
 * Can only be moved over via flying or jumping.
 * Sometimes found encasing an item.

Key Blocks

 * Acts like metal blocks.
 * Requires a key to unlock.
 * Cannot be flown over.
 * Small chance to drop a random pickup when unlocked.

=Indestructible Hazards=

Spikes

 * Can be walked over, but will damage Isaac in the process.
 * Deal one heart of damage upon contact with the player (unless the player has the Callus trinket, the ability to jump, or flight).
 * Sacrifice Room spikes will damage Isaac even with flight.

Retractable Spikes

 * Retract and extend on timers.
 * Can be walked over safely while they are retracted.

Wall Hugger

 * Moves and follows obstacles around it.
 * Stops moving when it encounters a Fire. Continues moving if the fire is destroyed.
 * When Isaac enters a room, the spikes will be retracted into the block and will extend after one second.
 * Can be randomized into an enemy by the D10, but upon re-entering the room, will turn back into a spike block.

Slide

 * The spikes rush towards Isaac if they are aligned with him in any of the four cardinal directions. They are able to "predict" that Isaac will walk in front of them, and will trigger accordingly.

Trivia

 * Slides are similar to spike blocks found in The Legend Of Zelda.

Poky

 * Slides around the room aimlessly.
 * May move towards the player if the player is near enough.
 * Is destroyed when the room is cleared.
 * Often appears during the Loki fight.

Pitfall

 * When Isaac falls into a pitfall, he takes damage and pops back out after a short delay.
 * Suction pitfalls attract Isaac and are most often found in trap rooms with Silver Buttons.
 * Pitfalls are spawned by several of Little Horn's attacks.
 * Flight makes Isaac immune to pitfalls.

= Destructible =

Rocks

 * Blocks movement and projectiles.
 * Can be destroyed with explosions and certain items like the Notched Axe, The Nail, Leo, or Thunder Thighs.
 * Can fill in a 1-block wide gap when pushed in the right direction by an explosion, or with one of the abilities that allows destruction by walking onto the rock.
 * Note: With these items, it is important to walk in the direction of the gap.
 * Small chance to reveal a Crawl Space when destroyed.

Tinted Rocks


Sometimes referred to as "Marked Rocks", they are always marked with an "x", and in some levels slightly tinted/discolored. These rocks are much less noticeable in The Womb and Utero due to them being the same color as the surrounding rocks, but can still be distinguished by the "x" on the bottom right. Destroying 100 tinted rocks will unlock The Small Rock.

Found in: Every Stage

Tinted rocks have a chance to spawn 1-2 of the following when destroyed:
 * Soul hearts
 * Keys
 * Bombs
 * Golden chests (only one)
 * A combination of any of the items mentioned above
 * The Small Rock (after it is unlocked) (Sometimes spawns with additional pickups, but cannot spawn alongside chests.)

Super Special Rocks


Super special rocks are tinted rock variants which are much harder to spot, as they have a smaller mark and are not discolored. Super special rocks takes two bombs to blow up, and drop the contents of two tinted rocks.

Super special rocks are unlocked by:.

Bomb Rocks


Act like rocks.

Found in: Low chance of replacing any rock.

Bomb rocks can be found anywhere a normal rock can spawn. They can only be destroyed by explosions and "stompy" items, like normal rocks. When they are destroyed, they create an explosion. Note that destroying a bomb rock next to a hole does not create a bridge as with normal rocks.

Urns


Act like rocks.

Found in: Urns have a chance to spawn the following when destroyed:
 * 1-3 Spiders
 * A few coins
 * A Quarter
 * Swallowed Penny

Mushrooms

 * Act like rocks.

Found in:

Mushrooms have a chance to spawn the following when destroyed:
 * Pills
 * Poisonous gas, which knocks back Isaac and deals a half-heart damage. (This does not count as an explosion.)
 * Liberty Cap
 * Magic Mushroom
 * Mini Mush
 * Mushrooms.

Skulls


Act like rocks.

Found in:

Skulls have a chance to spawn the following when destroyed:
 * Host enemies
 * Mushrooms (they can replace Hosts)
 * Tarot cards
 * Black hearts
 * Runes
 * Dry Baby
 * Ghost Baby

Polyps
Act like rocks.

Found in:

Polyps have a chance to spawn the following when destroyed:
 * 6 red tears in all directions and a puddle of bloody creep
 * Blood Clot
 * Placenta
 * Umbilical Cord
 * Harlequin Baby
 * Heart Pickups

= Destructible Hazards =

Fireplace

 * Deals a half-heart of damage when touched.
 * Can be extinguished by tears, bombs, or explosions.
 * Chance to drop coins or hearts when extinguished.

Red Fireplace

 * Can shoot red projectiles at medium speed at Isaac.
 * They do not telegraph before firing shots.
 * Shots fired from a Red Fireplace will not spawn directly on the Red Fireplace, but rather near the fire.
 * If Isaac stands too close when a Red Fireplace shoots, the bullet will spawn on Isaac, thus the bullet can't be dodged.
 * Can be extinguished like normal fireplaces.
 * Chance to drop coins or hearts when extinguished.
 * Can rarely replace normal Fireplaces.

Blue Fireplace

 * Chance to drop a soul heart when extinguished.
 * Can only be put out by bombs/explosions.
 * Can also be extinguished by The Adversary's Brimstone and earthquake attacks.

Purple Fireplace

 * Fires purple homing tears at Isaac.
 * Chance to drop a soul heart when extinguished.
 * Can only be put out by bombs/explosions.
 * Can rarely replace Blue fireplaces.

TNT

 * Blocks movement.
 * Can be destroyed by tears or explosions.
 * Explodes when destroyed.
 * Small chance to drop a Match Stick or a Burnt Penny when destroyed.

Pushable TNT

 * Can be pushed around by Isaac and enemies.
 * Can be destroyed by tears or explosions.
 * Explodes when destroyed.
 * Occasionally replaces normal TNT.
 * Can be spawned with Mine Crafter.
 * Will explode when pushed into fire.

Cobweb

 * Slows Isaac's movement.
 * If Isaac possesses flight then they have no effect.
 * Can be destroyed using explosions.

= Poops =

Poop

 * Can be destroyed by tears or explosions.
 * Has a small chance to drop coins, hearts, or Petrified Poop when destroyed.
 * Can fill in a gap when pushed in the right direction by an explosion, or by walking into them with Leo/Thunder Thighs to create bridges.
 * Can be created by The Poop.
 * If a Black Fly stays around Poop for long enough, it will morph into a Pooter.

Corny Poop

 * Has a small chance to drop coins or hearts when destroyed.
 * Has an Eternal Fly orbiting it that will become a Large Attack Fly upon destruction of the poop.

Red Poop

 * Deals a half-heart of damage when touched.
 * Leo/Thunder Thighs allows Isaac to walk over and destroy red poop without taking damage. Isaac will still take damage if he is standing on it when it reforms.
 * Drops nothing when destroyed.
 * Reforms in 3 seconds after being destroyed.
 * Normally produced by Carrion Queen, but can also be found in specific room configurations in The Womb, Utero, The Chest, and found in a certain room in The Basement.

Golden Poop

 * Harder to destroy than the normal poop.
 * Drops 5-9 coins or the Counterfeit Penny trinket when destroyed.
 * Can be created by The Poop if Isaac also has Midas' Touch.
 * If a Black Fly comes in contact with a Golden Poop, it will turn into a Pooter.

Rainbow Poop

 * Causes a rainbow to appear on the screen when destroyed; pauses the game for a second while playing a jingle.
 * Restores all of Isaac's red heart containers.
 * Rainbow Poop provides no benefit for characters without red heart containers such as ???.

Black Poop

 * Darkens the current room as if Curse of Darkness was active for a few seconds when destroyed.
 * Deals 10 damage and applies the 'Confusion' status effect to all enemies in the room when destroyed.

= Buttons =
 * See the normal button page.


 * See the silver button page.

= Unlockable Achievements =

Obstacles