D2R Data Guide
Schema reference for Diablo 2's game data files.
The canonical *.txt game-data tables that drive Diablo 2's engine, broken down by purpose. Each entry is a one-paragraph orientation; click through for the full schema, columns, gotchas, and cross-references.
Items
Base-item definitions, affix pools, the rules that pair them, and the gem/rune tables. The item system is the most interconnected corner of the data: an armor row references itemtypes for inheritance, automagic walks the prefix/suffix pools to decide what can roll, and gems powers both the gem-socket system and runeword construction.
Monsters & World
How monsters are defined, how their stats scale by level, and where they appear. The boss/area systems compose: superuniques reference a monstats row as their base, levels lists which monstats rows spawn there, and monlvl is the multiplication table the engine applies on top.
Mechanics
The cross-cutting systems that everything else hooks into: skills, XP, the stat encoding layer, the item-type taxonomy, and the cube. These tables are how the engine's "physics" is configured; touching them changes behavior across the whole game.