Terraria user Surfpup has created a mod for the game called tConfig. Terraria has more variables than a calculus course that dictate things like a magic spell’s power, the length of Potion Sickness, values of items, recipes, projectiles, and NPCs…literally any variable in the game. You can also add new items and projectiles with new sprite images as well.

The first time you run it, it will generate all the config files in the same location as the Terraria save files. This mod will take slightly longer to load the game since it loads a lot of data from files.

  • Multiplayer is disabled for now, so this can’t be used for cheating on servers
  • The only attribute of items that is saved on your character and worlds is the name, so as soon as you change a config file, it will change once the game is reloaded.
  • Keep in mind that items can disappear from your inventory, or turn into a copper shortsword with no description, if the config file for the item is deleted, can’t be loaded, or is renamed.
  • In order to add images, drop a .png file into the Item folder with the same name as the item, and set the item’s “type” value to -1.
  • You can add armor – see the Red Hero’s Outfit example, now included in the “Simple Example” mod pack folder in the download.
  • Custom items will only be loaded from Mod Packs.

This is the official thread: http://www.terrariaonline.com/threads/surfpups-config-mod.52207/
This is the official download link: http://dl.dropbox.com/u/10617177/SurfpupsConfigMod.zip
This is a backup download link in the event his dropbox bandwidth is used up: JOB download link