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.

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. This feature is experimental, and requires that  is set to "true" in the config.json settings. 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.

05162020
05162020 is a secret joke seed that creates an extremely strange world upon generation. It is also unique in that worlds created with this seed are not identical - if two worlds are created with this seed entered, they will not generate the same.

While 05162020 is generating, the background on the Menu will become that of the Glowing Mushroom Biome, the Moon will become a glowing face, all clouds begin to resemble Redigit's head, the generation descriptions become random numbers that change every tick (except when "placing traps"), and the outline of the progress bar rapidly flashes between Corrupt and Crimson

While 05162020 is active, a unique music track plays in every biome, the Moon Lord Legs item can generate in Chests, the Party Girl replaces the Guide upon entering the world for the first time, both the Corruption and Crimson generate in the world, and the dungeon generates underneath a "dead" living tree.

History
世界种子