World
The term world refers to Terraria's virtual world system which all of the gameplay takes place in. The world holds the entirety of the game content, such as items, enemies, objects, and so on. Terraria worlds are two-dimensional and navigated in a platform game-like manner. World appearance is subject to some settings.
The term map is partly synonymous with "world" but also refers to the minimap, the in-game map system.
Selection
After selecting a character to play with, the player will enter the world selection menu, where they select a world to enter.
In the menu, the following stats and features of a world are listed: name, (Desktop, Console and Mobile versions) icon, difficulty, size, and the date when the world was created.
When a Journey Mode(Desktop, Console and Mobile versions) character is selected, all non-Journey Mode worlds will be dimmed out and listed at the end of the world list, and vice versa. Selecting these worlds will result in the following messages:
- Journey Mode character to non-Journey worlds: "Only Non-Journey characters may enter a Non-Journey world."
- Non-Journey Mode character to Journey worlds: "Only Journey characters may enter a Journey world."
Several options are presented for an existing world:
Play: enter and play in this world.- (Desktop, Console and Mobile versions)
Favorite / 
Unfavorite: mark or unmark this world as favorite. Favorited worlds will be listed at the front of the world list, and cannot be deleted. 
Move to cloud / 
Move off cloud: move the world to or off Steam Cloud. Worlds saved in Steam Cloud can be accessed on different devices.- (Desktop, Console and Mobile versions)
Copy Seed: view and copy the seed of this world. - (Desktop, Console and Mobile versions)
Rename: change the name of the world. 
Delete: delete the world.
World icons
In the world selection menu, each world has a tree icon that represents its contents and progression: The left half always represents the world's naturally spawned evil biome, while the right is a pure Forest tree. In Hardmode, the bottom right quarter and half of the left branch will turn yellow, representing The Hallow. Worlds in which the Moon Lord was defeated gain a special golden border around their world icon, indicating the completion of player progression.
Corruption world icon.
Crimson world icon.
Hardmode Corruption world icon.
Hardmode Crimson world icon.
In some secret world seeds, both evil biomes are native to the world, resulting in a tree that is both Corrupt and Crimson with no pure representation. Other secret world seeds have completely unique world icons.
Creation and access
Creation
World creation is accessed by pressing the "New" button in the world selection menu. This presents the player with a multitude of customization options:
| Option | Description ( Desktop 1.4.0.1)
|
|---|---|
 World name |
Give your world a name! You can always change it later if needed! Randomize your world's name. |
 World seed |
The DNA marker that defines your world's specific shape and traits. Randomize your world's seed. |
| World size | |
Small  |
|
 Small     / Expanded |
Ideal for a quick, single player experience. |
 Medium |
Bigger and better for prolonged exploration, or bringing a friend. |
 Large |
Super-sized for long term progression and multiple players. |
| Difficulty | |
 Journey(Desktop, Console and Mobile versions) |
With great power comes great responsibility (Unearth your creativity) |
 Classic |
Your Adventure Begins... (The Standard Terraria Experience) |
 Expert(Desktop, Console and Mobile versions) |
Fortune & Glory, Kid. (Far Greater Difficulty & Loot) |
 Master(Desktop, Console and Mobile versions) |
Game over man, game over! (Brutally hard, for the truly brave) |
| Evil biome | |
 Random |
Let nature decide whether corruption or crimson infects your world. |
 Corruption |
Disease-like corruption is guaranteed to be present in your world. |
 Crimson |
Macabre, grotesque crimson is guaranteed to be present in your world. |
World name and seed may be randomized by selecting the button with the icon.
World creation is finished by pressing the "Create" button. It is followed by an automated process which generates a random world (if world seed is not used). This seeks to ensure that no two worlds are identical, allowing each new world to be a somewhat new experience. The perhaps largest difference between worlds is that some of them generate with the Corruption whereas others generate with the Crimson. Each of these evil biomes offer the player unique materials, enemies, and drops.
Access
Only one world can be accessed at a given time (in a similar fashion to how the player may only control one character at a time), but the player is free to create as many worlds as they can store on their device or computer. Characters are not locked to worlds (with the exception that Journey Mode(Desktop, Console and Mobile versions) characters can only enter worlds on Journey difficulty), so it is, for example, possible for an end-game character to play in worlds that have not made that much progression, or to bring resources from one world to another.
Since the contents of a character's inventory, Piggy Bank, Safe, Defender's Forge(Desktop, Console and Mobile versions), and Void Vault(Desktop, Console and Mobile versions) are stored with the character, the character has access to these no matter which world they visit.
A given world can be used both for single-player and multiplayer. In the case of the latter, the world is used to make a server (see Guide:Setting up a server).
When entering a new world, the character will appear at the world's spawn point, usually on the surface close to the horizontal mid-point of the map, with an in-game time of 8:15 AM. A character's individual spawn point can be altered using a Bed. If the player dies or teleports using a Recall Potion, Potion of Return(Desktop, Console and Mobile versions), Ice Mirror(Desktop, Console and Mobile versions)/Magic Mirror, Cell Phone(Desktop, Console and Mobile versions), or Shellphone(Desktop, Console and Mobile versions), they will return to their spawn point.
The world is typically exited through the settings option that appears when the inventory is opened (see Game controls), though this depends on the game platform.
Generation
While a new random world is being generated, various texts appear over the loading bar, showing what is being generated in the world.
Structure and content
Worlds are structured into layers and biomes in order to provide various content depending on the player's location. World content is also provided through a range of time-based events like invasions, nighttime, boss battles, etc. The world states of pre-Hardmode and Hardmode also determine what content is available. The world's biomes and layers, time-based events, and Hardmode are designed to gradually become accessible as the player becomes more skilled and the character stronger. This progression gameplay can pose a unique challenge in multiplayer, as one player could progress more quickly than the others, only to find themselves with a weak team during difficult battles.
World content is also dependent on game platform. 
Old-gen console and have exclusive content not found on other platforms, and vice-versa.
Name
During the creation of the world, the player may opt to let the game create a random name for the new world by clicking the sign icon to the left of the name field. It will then replace the text in the field with a random name that is created using the schema below. The name will never be longer than 27 characters. There is a 1/10000 (0.01%) chance for the random world name to be The Constant.[1]
The game will pick a random composition and random adjectives, locations, and nouns from the lists below. The first two compositions are twice as likely to be picked as the others.
This content is transcluded from World/Name.
| Composition | Random examples ( to generate new ones) |
|---|---|
| The <adjective> <location> of <noun> |
|
| <Adjective> <location> of <noun> |
|
| The <adjective> <location> |
|
| <Adjective> <location> |
|
| The <location> of <noun> |
|
| <Location> of <noun> |
|
Adjectives
|
Locations
|
Nouns
|
Notes
- Worlds can be viewed and sometimes edited by third-party programs known as map viewers.
- If the player attempts to quit a world after defeating Wall of Flesh but before the Hardmode biomes are generated (i.e. before the "The ancient spirits of light and dark have been released." is displayed), the loading description "Setting hard mode"[sic] will appear and the player has to wait for the game to generate the Hardmode biomes before returning to the main menu.
- Worlds, like characters, are stored as individual files. A world has the file extension
.wld.- On
Windows, they can be found in the directory %USERPROFILE%\Documents\My Games\Terraria\Worlds. - On
Android, they can be found in the directory Storage/emulated/0/Android/data/com.and.games505.TerrariaPaid/Worldsand can be accessed in a file browser.- Note: Android phones running Android 11 or higher will likely need an external app to access the
Storage/emulated/0/Android/data/folder. Alternatively, it can be accessed through a separate device, such as a computer via USB.
- Note: Android phones running Android 11 or higher will likely need an external app to access the
- Windows Steam users who have their worlds moved to the Steam Cloud will find them under, for example,
C:\Program Files (x86)\Steam\userdata\<userID>\105600\remote\worldsby default. See this Steam article for world locations in the Mac and Linux versions of the game.
- On