Ultima Underworld Editor
Produced by: krokots
Website: Ultima Underworld Editor – Release @ GOG
A utility for editing all nine levels of the Abyss in Ultima Underworld, importing new graphics to the game, and modifying game data.
Source code for krokots’ Ultima Underworld editing utility.
This Windows-based utility is, at present, a nearly full-fledged editor for the first Ultima Underworld game. It allows players to fully edit all nine levels of the Stygian Abyss, to the point that nine brand new levels could in fact be created. A conversation editor is also included, and the utility supports importing custom textures and sprites as well. String and object data in the game can also be modified, enabling users to modify mantras, add new scrolls and books, and modify monster statistics (among other things).
Some hard-coded features of the game cannot be changed at this time, however; the player always starts in the same place on the first level of the Abyss, for example. The mana drain on the seventh level, and the shaking and health drain on the ninth level, are also unavoidable. Certain puzzles in the game are also not able to be modified, and some conversation features are missing.
As one might expect, users will need to have Ultima Underworld installed to make use of this utility. Because some aspects of the editor are a bit of a challenge to use effectively, the creator has posted a pair of videos (1, 2) to YouTube, which explain the use of the editor.


























































there should’ve been a parade in the streets over this
Very cool! Does this work with Ultima Underworld II?
Hey, I’ve been using the Ultima Underworld Editor and I’ve noticed that when changing any enchantments on equipment if the enchantment is “Protection” or “Toughness” the engine is adding an extra 32 to the enchantment. IE “Lesser Protection” is 704 and “Protection” is 705. The moment I change the enchantment from “Lesser Protection” to “Protection” the Quality jumps from 704 to 737, but it should change from 704 to 705 and the engine flags it as “Unknown”.
So I found an issue with the Underworld Editor, when moving items around with the editor sometimes it looses track of an item and when that happens it usually causes issues. I had to delete the affected items and then create new ones. Also, I meant quantity before, not quality. Thanks!
• What is happening: While reading the level files, the code is encountering conflicting data entries. It states that multiple data pointers are pointing to the exact same memory/file indices.
• The Cause: This points directly to corrupted structural integrity in the underlying lev.ark or data map file you are editing. When a container or tile cell is being parsed, the slot indices (such as index 704, 856, 797) are duplicate entries. As a result, the tool forcefully overwrites existing objects in the editor’s memory cache to make room. Here is the log…
https://drive.google.com/file/d/1pZb9efCxTy3Vxmfe5-6RPiBHjXtNvhqZ/view?usp=sharing