📋 Printable · Keep this open while you build

Terraria Modding Cheat Sheet
Everything on one page

Folder paths, the world tools, the biome rules and the common log errors. Print it or keep the tab open while you work through the Terraria World Workshop.

🖨️ Print this sheet 🌳 Back to the Workshop
🐯
Ember says: you do not need to memorise any of this. Bookmark the page, and come back when a folder path or a red line confuses you.

1. What you need

Costs
Terraria (the game)      paid, once, on PC
tModLoader (mod loader)  free
TEdit (world editor)     free
A computer               Windows, Mac or Linux

2. Where the Worlds folder lives

Worlds folder
Windows:  Documents\My Games\Terraria\Worlds
Windows (tModLoader): Documents\My Games\Terraria\tModLoader\Worlds
Mac:      ~/Library/Application Support/Terraria/Worlds
Linux:    ~/.local/share/Terraria/Worlds

3. What a world file holds

A .wld file
MyWorld.wld
├── tiles        foreground blocks (what you stand on)
├── walls        background walls (stop enemy spawns)
├── chests       stored items
├── signs + NPCs metadata
└── header       world name, size and version

4. The build checklist

Every time you edit a world
1. Copy the world first (backup)
2. Open the COPY in TEdit
3. Change one thing
4. Save as a .wld
5. Load it in the game
6. Check it looks right, then repeat

5. Biome rules (roughly)

How a biome is counted
Forest    plenty of grass + trees
Desert    lots of sand
Snow      lots of snow and ice
Ocean     water at the edge of the map
Jungle    jungle grass and mud
A biome needs ENOUGH of its blocks nearby.
A few tiles is not enough.

6. Common log errors and fixes

tModLoader log
BadImageFormatException
  -> The mod was built for another game version.
     Update tModLoader and rebuild.

"created with a newer version"
  -> Update Terraria, or edit a world that
     matches your version.

Duplicate mod / nested twice
  -> Move the inner folder up, so the mod's
     own files sit directly in the folder.

World will not load
  -> Restore your backup copy and try again.

7. Quick words

Words you will hear
tile       one square of the world
wall       the background behind a tile
biome      a region counted from its blocks
TEdit      the free world editor
tModLoader the free loader for mods
.wld       the world file you save and share
🛠️
Practise with no install: the Terraria World Studio runs in the browser, so you can try every idea on this sheet before you touch TEdit.