You can choose Corruption or Crimson only when the server runs TShock. On Vanilla and tModLoader the game picks one at random, whatever you choose. The choice also counts only for a new world. A world that already exists keeps the evil it was made with.
Why the form can mislead you
The New world form on the World page shows World evil for every server program. On Vanilla and tModLoader the form accepts your choice and then ignores it. Check which program the server runs before you make the world.
Make a world with the evil you want
- Open the World page.
- In Server software, check that TShock is the one running. If not, choose it and confirm Run TShock?. TShock downloads at the next start. Your worlds and the other programs’ files stay.
- In the New world card, type a Name.
- Choose Size and Difficulty.
- In World evil, choose Corruption or Crimson. Random leaves it to the game.
- Choose Make this world.
- Start the server. If it is running, restart it: that drops everyone who is on, so first send a note with Message everyone on the Players page. Start and Restart are at the top of the server page. The world is made at the next start, and the server plays it. A large world takes a minute or two.
- Name
- World evil
- Make this world
Type the Name (1), set World evil (2), then choose Make this world (3). World evil shows as Random until you change it.
Your other worlds stay on the server. See make a new world.
The same setting on Startup
The Startup page also has a World evil variable. Its values are random, corrupt and crimson. It says it is for a new world on TShock. Changes apply at the next start.
After the world is made
The Worlds list shows the tag Corruption or Crimson on the row. Worlds are shared between the three programs, so you can switch the software afterwards. Two cautions:
- tModLoader runs Terraria 1.4.4. A world saved by 1.4.5 shows Too new for tModLoader and does not open there.
- TShock joins with the normal game only once TShock has caught up with a game update.
The first TShock start prints a one-time code. See the TShock setup code.
If it does not work
- The world came out with the other evil. The server was not running TShock when the world was made. Delete that world if you do not want it, switch to TShock, and make it again under a new name.
- You cannot choose it for an old world. The panel has no way to change a world’s evil after it is made. Make a new world.
- The name is refused. A world with that name is on the server already. Choose another name.
More about the game: Terraria servers.