Belly Jelly is an unlockable passive item in The Binding of Isaac, added in the Repentance DLC.

Enemies and projectiles that touch Isaac have a 50% chance to bounce off of him and propel in the opposite direction. When this happens, damage to Isaac is negated.

Bounced off enemies will take damage upon hitting a wall or an obstacle, or another enemy. The damage is equal to 8 + 2 × CurrentFloor.

Only enemies that normally deal contact damage can be bounced off.

Bounced off projectiles deal 6 damage if they would deal half a heart of damage, or 7 if they would deal a full heart.

Lasers cannot be bounced off.

The bouncing mechanic also works for Fire Places and spikes enemies such as Poky, Slide and Grudge, granting a chance to avoid unintentional damage.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this item for the previous Repentance version, check this page instead.

Defeat The Beast as Tainted Magdalene.

Belly Jelly can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for Belly Jelly have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Belly Jelly

• Enemies that touch Isaac are bounced back in the opposite direction
• Chance to not take contact damage from enemies that are bounced off
• Chance to reflect enemy projectiles
• Abyss: x1 knockback locust 1.5x Isaac's damage

• Check out the item description on the external Isaac Wiki.