Broken Padlock is a trinket in The Binding of Isaac, added in the Repentance DLC.

Doors that require a pickup in order to unlock can be opened up with explosions instead.

This also includes any types of chests, even if they don't require a pickup, except Haunted Chests and Mom's Chest.

Also works on Key Blocks and the Strange Door in Depths II.

Doors that require 2 keys only require one bomb to open.

Locked doors can be bombed through even before the room has been completed.

Mega Chests require multiple explosion in order to open.

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

The following special synergies and interactions for Broken Padlock 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.

Broken Padlock

• Locks can be broken open with bombs
• Golden Trinket (without Mom's Box): Challenge rooms and arcades can be broken open with bombs
• Mom's Box: Challenge rooms and arcades can be broken open with bombs
• Mom's Box + Golden Trinket: Challenge rooms, arcades, and boss rooms can be broken open with bombs

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