Secret Rooms

One of the many possible secret room layouts.

"If you find a crack in a wall, use a Blank to blast it down." - Bello

Secret rooms are hidden rooms that can be discovered in Enter the Gungeon. Every chamber has a 90% chance to generate with a secret room present, though it is possible for a chamber to have no secret room, or multiple secret rooms. Entrances to secret rooms can be opened with blanks, most things that trigger blank effects (such as armor), and certain explosives including the Bomb, Lil' Bomber and the explosion of a fused chest.

Upon shooting a secret room wall using a weapon that does not have infinite ammo, the wall will visibly crack. Entrances to secret rooms are also revealed by the Brick of Cash, the Map, Gungeon Blueprint, and the Insight synergy. Hearts can be pushed into unopened secret rooms when at full health (this may or may not work with other items).

Regular Secret Rooms

Every chamber has a 90% chance to generate a 'regular' secret room, which usually contains chests and pickups. These are the most common kinds of secret room that Gungeoneers will encounter. Secret rooms with higher Weight values are more likely to appear.

The chance of any given secret room being chosen is equal to the secret room's weight divided by the sum of the weights of all possible secret rooms.

Click expand to view Secret Room layouts.

Layouts
Image	Name & Contents	Weight
	Secret_Room_Random_001	15
	A random chest 1-4 random pickups
	basic_secret_room_001	15
	1-2 random pickups
	basic_secret_room_002	15
	A random chest on a central island, surrounded by a pit
	basic_secret_room_003	15
	1-2 random pickups on a central island, surrounded by a pit
	basic_secret_room_004	1
	3 Chests Chests in this room are extremely likely to be Mimics.
	basic_secret_room_005	1
	3 random chests
	basic_secret_room_006	1
	2 Random Unlocked Chests on a central island, surrounded by a pit. The island itself is covered in spike traps, with a patch of flame traps at its center.
	basic_secret_room_007	1
	5 random pickups on a central island, surrounded by a pit. The island itself is covered in flame traps, which trigger on an alternating timer, in a checkerboard pattern.
File:Basic secret room 008.png	basic_secret_room_008	1
	basic_secret_room_009	1
	1-4 random pickups and a random chest. This chest is always unlocked.
File:Basic secret room 010.png	basic_secret_room_010	1
File:Basic secret room 011.png	basic_secret_room_011	0.5
File:Basic secret room 012.png	basic_secret_room_012	1
	DeadGuy_secret_chest	1
	1 Brown chest (Unlocked), 1 Blue Chest, and 1 Green Chest 1 Key A note, and a human skeleton
	high_dragunfire_room_001	0.2
	Can only appear in the Gungeon Proper, if the High Dragun has been killed at least once.

NPC Secret Rooms

In addition to regular secret rooms, there are special secret rooms containing various NPCs that can appear. Every time a new run is started, one room from the below table will be chosen based on its weight, and assigned to a future floor. If EMPTY is chosen, at a weight of 0.8, then no NPC Secret Room will appear in the run.

The chance of any given NPC secret room being chosen is equal to the secret room's weight divided by the sum of the weights of all possible secret rooms. NPC Secret Rooms are handled completely separately to regular secret rooms, meaning that they can appear in addition to regular secret rooms.

Click expand to view NPC Secret Room layouts.

Layouts
Image	Name & Contents	Weight
File:NPC TruthKnower Room.png	NPC_TruthKnower_Room	0.01
	Brother Albern
File:SubShop EvilMuncher 01.png	SubShop_EvilMuncher_01	0.01
	Evil Muncher Can only appear if the player has used the regular Muncher more than 6 times.
	WhichRoomIsThis	0.05
	Witches Can only appear if the player has played the current save file for more than 4 hours, and has visited the Gungeon Proper more than 5 times.
File:NPC Monster Manuel Room.png	NPC_Monster_Manuel_Room	0.05
	Monster Manuel Can only appear if the player has avenged Ser Manuel by killing Blockner.
File:NPC Old Man Room.png	NPC_Old_Man_Room	0.05
	Old Man
EMPTY		0.8

Contents

Secret rooms can contain:

• Hearts
• Keys
• Armor
• Blanks
• Ammo
• Glass Guon Stones
• Chests
• Shrines
• NPCs, such as:
  • Old Red
  • Cursula
  • Professor Goopton
  • Flynt
  • Trorc
  • Winchester
  • The Lost Adventurer
  • Ser Manuel
  • Witches (can only be found in secret rooms)
  • Old Man (can only be found in secret rooms)
  • Brother Albern (can only be found in secret rooms)
• High Dragunfire (can only be found in secret rooms)
• Evil Munchers

Messages

Secret Rooms often contain notes along with chests or pickups:

Blobulonian Army Notes

• First Note

Lord Blobulolus,

The recruits you requested should arrive within the fortnight.

I hope their training is up to your rigorous standards.

To victory,

Fifth Regiment Quartermaster Blorp

• Second Note

Quartermaster Blorp,

This is most excellent news. Our Lord is most pleased.

Please consider this official notice of your promotion to Sr. Quartermaster of the Second Division.

Adjutant Osgoo

• Third Note

Dearest Plorp,

My heart subdivides to think of how long it has been since I laid eyes upon you.

I have been promoted, and they're moving me to the front. Know that I love you.

Yours, forever,

Blorp

• Fourth Note

0147:

Blorp has become a nuisance. When his transfer papers come in, do your best to lose them, eh?

-AO

Other Notes

• First Note

My past caught up with me, in the form of bullet wounds.

All that I have I leave to you, Stranger.

Goodbye, cruel Gungeon.

• Second Note

Well, I'm stuck. This time, I'm dead for sure.

But maybe... I've got a plan. And it's just crazy enough to work!

• Third Note

This could be a mimic. Anything could be a mimic...

The fear is crippling, the only way not to get mimic'd is to stand with my back in a corner, vigilant.

• Fourth Note

To whoever is perceptive enough to find this place:

I have left something here for you. Good hunting, adventurer.

• Fifth Note

The Gundead are closing in. I don't think I'm going to make it.

I don't want to die again. Waking up in the Breach... it's the worst feeling.

• Sixth Note

I can't do this any more. I'm just going to lay down my arms, here... and die.

Again.

• Seventh Note
  • This note is likely written by Frifle.

Well, I got stuck in another one of these damnable secret rooms.

Just gotta wait for Mauser to get back. Don't know what I'd do in this situation without him around.

• Eighth Note
  • This note was likely written by Alistair the Thunderbolt, mentioned in most lightning-themed items' Ammonomicon descriptions.

These walls don't stand a chance against me! Blanks? Who needs 'em?

-Thunderbolt

• Ninth Note

I thought I killed the past, but I'm still stuck in this place.

Wrong gun, I guess. I'll leave it here.

• Tenth Note

Too much to carry. Making a note of this spot on my map, so I can come back later.

• Eleventh Note

If I stay here long enough, the walls should shift...

Eventually, it'll put me right in the exit! Genius!

• Twelfth Note

I don't like the way the Gundead look at me, with those soulless eyes... so low on their head.

I think I'll just stay here for a bit.

Notes

• The Resourceful Rat will not attempt to steal any pickups in the secret rooms.
  • He will, however, still take items dropped by the player inside the room.
• Secret rooms are often connected to chest rooms, shops, elevator exits, and in dead-end rooms.
• Secret rooms can be revealed by Brick of Cash or by the Insight synergy between Huntsman and Trick Gun.
• Enemy bullets can reveal walls that lead to secret rooms.
• The number of shots fired before a secret room wall begins to crack depends on the damage of the gun used. Lower damage guns will require a few more shots before cracks begin to appear.
• The Abbey of the True Gun may spawn another secret room in addition to the secret room containing Brother Albern.
• The Old Man may appear on any floor, causing that floor to have an extra secret room.
• Secret Room entrances tend to not be behind Objects.
• Secret room entrances will never spawn inside the room containing the Old Crest or the room leading to the Abbey of the True Gun.
• Despite the eighth note's boast, nothing in the Thunderbolt's implied loadout (Shock Rounds, Void Core Assault Rifle, Void Core Cannon and Void Shotgun) can breach Secret Rooms without using a Blank.
• Walls that hide secret rooms have slightly different color compared to surrounding walls. This is most noticeable in treasure rooms, allowing for slightly easier identification.

Gallery

• 

  A secret room that generated off a Shop, adopting the Shops tileset

• 

  A secret room that generated containing only a single Blank pickup, resulting in no net gain if a blank was used to enter

Trivia

• Prior to the Supply Drop Update, Blasphemy's melee attack could reveal secret rooms despite having infinite ammo.