Goop
A variety of liquids, known as Goop, can be found in the Gungeon. Sources of goop include items, guns, objects, and enemies.
All goop besides oil can be used to put out fuses on chests and the fireplace in the Keep of the Lead Lord. Gungine and Plunger restore ammo if reloaded while standing on any goop.
Water
Water is a common type of goop that has no effect on its own. Sources of water include:
- Water barrels
- Ice bombs
- Items:
- Guns:
- Enemies:
Electrified Water
If water is electrified, it will continuously deal damage to enemies and players standing in it. Unlike fire and poison, this will not deal damage to flying enemies such as Gigi. Sources of electricity include:
- Battery Bullets
- Cobalt Hammer (when charged)
- Laser Lotus
- Shock Rifle
- Thunderclap
Shock Rifle, Hazmat Suit, Battery Bullets, Clearer Guon Stone, and Neo Tech, Yo provide immunity to electricity.
Ice
Water can be frozen into ice, which makes it very slippery unless the player has Heavy Boots. Water can be frozen by:
- Heart of Ice
- Freeze Ray
- Frost Bullets with any explosive weapon
- Frost Giant
- Glacier
- Ice Breaker
- The Judge (ice bullet)
- Mailbox (ice package)
Poison
Poison goop poisons enemies and players that stand on it. Sources of poison goop include:
- Poison barrels
- Coffins
- Items:
- Big Boy
- Bug Boots
- Irradiated Lead with any explosive weapon
- Monster Blood
- Poison Vial
- Guns:
- Gamma Ray (with Gungeonite)
- The Judge (poison bullet)
- Mailbox (poison package)
- Plague Pistol
- Plunger
- Poxcannon
- Shotgrub
- Shotgun Full of Hate
- Trashcannon
- Enemies:
Oil
Oil is normally harmless, but will be set on fire upon contact with fire or an explosion. Sources of oil include:
- Oil barrels
- Oil lamps in the Black Powder Mine
- Braziers (automatically ignited)
- Items:
- Hot Lead with any explosive weapon (automatically ignited)
- Molotov (automatically ignited)
- Napalm Strike (automatically ignited)
- Guns:
- Fossilized Gun
- Gungeon Ant
- Microtransaction Gun (Convict figurine, automatically ignited)
- Molotov Launcher (automatically ignited)
- Mourning Star (automatically ignited)
- Enemies (all oil spawned by enemies is automatically ignited):
Green Fire
Green fire is a special variant of fire that does not damage the player, and enemies ignited by green fire will permanently burn. Spreading oil onto green fire will replace it with regular fire.
Sources of green fire include:
Cheese
Cheese rapidly slows and freezes any enemies that walk into it. Enemies that die while encased in cheese will spawn another cheese pool.
The only sources of cheese are Elimentaler, Resourceful Sack, and Chamber Gun in the Resourceful Rat's Lair.
Web
Webs slow the player's movement, but will be destroyed when the player moves off of them. Contact with fire will burn and destroy the web.
Webs randomly appear throughout the Gungeon, and are spawned by Phaser Spiders.
Other
There are a few other types of goop which have no unique effects other than replacing any goop that had already occupied the floor.
Blobulons, Blobuloids, and Blobulins leave behind trails of red goop while chasing the player. The same goop is spawned by the Bait Launcher.
Mutation and Bloodbulons leave trails of dark red goop.