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 (not to be confused with the big map that takes up the whole screen).
Creation and access
Worlds are created and accessed in the game's main menu. After selecting single- or multiplayer and a character, the player is provided the options of selecting (for playing) already created worlds if they have made any, creating new worlds, favoriting worlds, integrating worlds with their Steam Cloud in order to easily access them on different computers, and deleting them.
Creation
World creation presents the player with the following options (also see images on the right). Options slightly differ between game platforms.
| 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 |
With great power comes great responsibility (Unearth your creativity) |
 Classic |
Your Adventure Begins... (The Standard Terraria Experience) |
 Expert |
Fortune & Glory, Kid. (Far Greater Difficulty & Loot) |
 Master |
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 some of them having the Corruption whereas others have the Crimson. Each of these evil biomes offer a player unique materials, enemies and drops.
World icons
|
| The special golden border of post-Moon Lord worlds. |
Each world will have a world icon that depicts its contents and progression, which is shown in the world selection menu. Worlds created with secret world seeds will have special world icons. On the Desktop version, 
Console version, and 
Mobile version, worlds with Moon Lord defeated will have a special golden border around its world icon.
All regular world icons:
Corruption world icon.
Crimson world icon.
Hardmode Corruption world icon.
Hardmode Crimson world icon.
Access
Only one world can be accessed at a given time (in 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 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, and Void Vault 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 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, Magic Mirror/Ice Mirror, or Cell Phone, they will return to their spawn point.
World exit is typically done through the settings option that appears when the inventory is opened (see Game controls), though this depends on game platform.
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 0.01*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.
- Worlds, like characters, are stored as individual files. A world has the file extension
.wld%USERPROFILE%\Documents\My Games\Terraria\Worlds" directory. For some official mobile users, they are located in "Storage/emulated/0/Android/data/com.and.games505.TerrariaPaid/Worlds" and can be accessed in a file browser.- Windows Steam users who have their worlds moved to the Steam Cloud will find them under "
C:\Program Files (x86)\Steam\userdata\<userID>\105600\remote\worlds" by default. See this Steam article for world locations in the Mac and Linux versions of the game.
- Windows Steam users who have their worlds moved to the Steam Cloud will find them under "
Trivia
- The leaves of the tree icon when selecting a world will change depending on the status of the world. The left half will always represent the world's naturally spawned evil biome, while the right will be a pure Forest tree. In some secret world seeds, both evil biomes will be native to the world, resulting in a tree that is both Corrupt and Crimson with no pure representation. In Hardmode, the bottom right quarter and half of the left branch will turn yellow, representing The Hallow.