World Seed

The World Seed feature enables the display of the random seed used to generate a Terraria world, and allows the user to input a custom seed manually when generating a new world.

Worlds generated with Terraria 1.3.4 and later will always have a seed regardless of settings; The experimental feature setting merely allows the user to see, copy, and input them. If a seed is not entered manually during world generation, a seed is automatically generated randomly. Worlds generated prior to 1.3.4 will never have a viewable seed: while they were generated with a random seed, that information was only used during world creation, and was not stored in the world file.

Worlds created after 1.4.0.1 will always be able to have their seeds edited upon world creation, regardless of the experimental feature setting.

Some special seeds have been discovered as easter eggs that generate worlds with strange and unique features.

Copying seeds from created worlds
Worlds with a seed display a small seed icon in the world list, allowing the user to see that world's seed and copy it to their computer's clipboard. A copied seed can then be input when generating a new world, which results in a nearly identical generated world, provided it is generated with identical parameters (same size, same choice between Corruption and Crimson, and same choice of difficulty).

World seeds are formatted like this:.

Size:
 * 1, if World size is Small.
 * 2, if World size is Medium.
 * 3, if World size is Large.

Difficulty:
 * 1, if World Difficulty is Classic.
 * 2, if World Difficulty is Expert.
 * 3, if World Difficulty is Master.
 * 4, if World Difficulty is Journey.

World evil:
 * 1, if World Evil is Corruption.
 * 2, if World Evil is Crimson.

Identifier: The actual unique random seed.

This formatting can be used to automatically set all the initial settings of a world to be as desired.

Special seeds
There exists certain special seeds able to generate worlds with features differing from normal gameplay. These changes can wildly affect world structures and biomes, certain game mechanics and even the music being played.

Worlds created with these seeds will not be identical despite having the same seed.

Drunk World


This seed references the date of 1.4's official release, 5/16/2020, and generates a strange world referred to in the source code as "Drunk World."
 * Seed:  or


 * While 05162020 is generating:
 * The background will change to that of the Glowing Mushroom biome.
 * The Moon will become a glowing face from "The Moon, Venus and Jupiter will be aligned to form a smiley face on May 16, 2020" (which is also the release date for 1.4.0.1).
 * All clouds begin to resemble Redigit's head.
 * The generation descriptions and tips become random numbers that change every tick (except when "placing traps").
 * The outline of the progress bar rapidly flashes between Corrupt and Crimson.
 * When the world has been created, its icon shows a tree infected with both world evils, as opposed to normal worlds, icons of which show a tree that is partially infected with one of them.
 * While the world is active, all music is replaced with its counterpart from Terraria: Otherworld.
 * Both the Moon Lord Legs and Red Potion items can generate in Chests.
 * The Party Girl replaces the Guide upon entering the world for the first time.
 * Both World evils (each on opposite sides of the world).
 * Both ore variants generate in the world.
 * Marble and Granite caves swap their structures.
 * The Jungle and Snow biomes generate on the same side opposite of the Dungeon.
 * The Dungeon generates underneath a "dead" Living Tree which is painted red, yellow, blue, or purple.
 * The surface entrance is completely removed, making it harder to defeat Skeletron.
 * Both the Corruption and Crimson Biome Chests will be included.
 * The Dungeon itself is a reference to the popular Terraria YouTuber, ChippyGaming, and will generate with the Chippy's Couch furniture.
 * Despite the potential for The Old Man to be placed below 0 depth, entering the dungeon will not spawn any Dungeon Guardians.
 * As a result of this, it is possible to clear the dungeon before Skeletron has been defeated.
 * The Jungle Temple is painted green and is much larger in size.
 * Bee Hives are replaced with oversized variants, hosting multiple Larvas.
 * The Underworld will be inverted, with the middle third as a continuous lava lake and the two thirds at the edge containing structures.
 * The surface generates an abundance of Living Trees, many of which are clustered and interconnected underground.
 * Sky islands are now either deserts with sand instead of dirt and/or snow biomes with snow instead of dirt with a corresponding Water Fountain.
 * Both Oceans have a much higher chance to generate as the ocean trench variant.

Trivia

 * The moon forming a smiley face in the world generation screen is likely a reference to a meme stating that "The moon, Jupiter and Venus will form a smiley face on May 16th, 2020."
 * The Moon Lord Legs item is exclusive to this world (and is likely Redigit's answer to a petition to add the Moon Lord's legs to the game).
 * The discovery of this seed originates from an image posted in a tweet by Redigit, featuring the release date and the new world generation screen.

Not the bees
This seed references a meme from the 2006 remake of the film The Wicker Man. It generates a world dominated by bee-themed biomes and bee-related items and structures.
 * Seed:  or   (case insensitive)


 * While generating, the generation descriptions all say "Generating Bees".
 * Forest is replaced with Jungle.
 * Hive Blocks replace Stone Blocks.
 * Honey Blocks replace Sand Blocks in the Ocean.
 * Hornets and Larva can appear everywhere.
 * The Dungeon is Painted orange.
 * The starting NPC is the Merchant instead of the Guide.
 * Queen Bee spawns at the edge of the world.
 * All Water is replaced with Honey.
 * The Desert and evil biomes are not affected.
 * The border between the Caverns and Underworld layers are always Glowing Mushroom biome.
 * Most of the Mud Blocks in the Glowing Mushroom biome are replaced by Crispy Honey Blocks.
 * The snow biome is composed solely of Hive blocks.

For the worthy
This special world's features aim to drastically increase the difficulty of the game.
 * Seed:  (case insensitive)
 * The world generation screen has backwards text.
 * Water pools throughout the world may be generated as lava pools instead.
 * The Demolitionist replaces the Guide upon entering the world for the first time.
 * Many bosses are much larger than normal, such as Skeletron, King Slime and the Destroyer.
 * Golem is much smaller than normal.
 * Pots drop lit bombs (the exploding kind, not the item).
 * Spider Nests, Granite Caves, Marble Caves, and Glowing Mushroom biomes are much more common.
 * Glowing Mushroom biomes are much larger in size.
 * Floating Islands are always infected with the world's evil, with matching water fountains.
 * Skyware chests within are replaced with locked Gold Chests.
 * The Dungeon generates painted with vibrant colors and filled with many more Spike traps.
 * The Jungle Temple is painted green and is much larger in size.
 * In the Underworld:
 * The ground is speckled with 1 block sized pockets of lava.
 * All Ruined Houses are made of Hellstone Brick.
 * All Demons spawned are replaced with Voodoo Demons.
 * Wooden chest loot can contain a single dirt block mixed in with everything else.
 * Red Potions can generate in chests. When consumed, these will now apply 3 random 30 minute buffs instead of applying all debuffs like in other world seeds.
 * Bosses have doubled health, on top of previous Expert/Master bonuses.
 * Enemies have increased health and massively increased damage. Demon Eyes pre-hardmode, for example, deal 40 damage to a character in full Solar Armor.
 * Bunnies are replaced with Explosive Bunnies.

History
世界种子