Glossary

Terms used across these docs, in alphabetical order. Each links to where it's explained in full.

• API version. The version of the mod API (T3SdkApi) an installed T3SDK implements. The table only grows, so a mod can check api->size before using a member added later. See The mod lifecycle.
• Archetype. An UnrealScript class (named D_<n>) that gives a placeable thing its default properties. A map actor of that class inherits the archetype's gamesys values and stores only what it overrides; T3Gamesys.t3u holds about 2,300 of them. See Game and engine: the gamesys property system.
• Borderless window. T3SDK's default display mode: a window with no border or title bar that covers the monitor, instead of the game's own exclusive fullscreen. Enables alt-tab, other monitors, screenshots, VSync in a window, and the level-change curtain (below). See Settings explained.
• Code mod. A .t3mod package with a DLL (entry in its manifest) that T3SDK loads into the game. Needs T3SDK installed, unlike a content pack (below). See Mod packages.
• Content pack. A .t3mod package that ships files instead of code, or alongside it — textures, loading screens, even a whole map — rather than a DLL. See Content and texture packs.
• Curtain (level-change curtain). T3SDK's fix for the gap when the game restarts between levels: a helper process keeps the outgoing loading screen on the monitor until the new game's own is ready. New, and not yet tried in the actual game. See Troubleshooting: display and performance.
• decomp.dev. The public dashboard that tracks how much of T3Main.exe has been matched, built from this repository by CI. See decomp.dev reporting.
• Flesh. Ion Storm's own name for the early Unreal Engine 2 fork Thief: Deadly Shadows runs on. See Assets and formats.
• Frame callback. A function a mod registers that T3SDK calls once per frame, on the game's main thread, from the point the engine is ready. See the cookbook's every-frame recipe.
• Gamesys. Ion Storm's own property system, layered on top of Unreal's own tagged properties, that stores extra per-object data (AI, physics, interactions). The map editor can change scalar gamesys values on an actor. See Game and engine: the gamesys property system.
• Ghidra. The disassembler and decompiler this project's reverse engineering runs on. See Decomp handbook: reverse engineering.
• .gmp. A map file, Content/T3/Maps/<Level>.gmp: one level's actors, BSP geometry, navigation data and gamesys property overrides, in Unreal's own package format. See Assets and formats.
• Hook. Code that redirects one of T3Main.exe's own functions to a mod's or T3SDK's own function first, with a trampoline back to the original. Every mod and T3SDK share one hook table, so a given function can only be hooked once. See The mod lifecycle.
• .ibt. A bundle of a map's textures and other resources. Experimental texture packs rewrite these in place. See Installing mods: texture packs.
• Load order. The order T3SDK loads mod DLLs in, top to bottom (System\mods\load-order.txt); when two mods provide the same file, the one lower in the list wins. Drag mods to reorder them on the Mods page. See Installing mods.
• Loose DLL. A mod DLL dropped straight into System\mods without a package around it. It still loads, after every packaged mod, but has no manifest, so the launcher can't check its requirements or conflicts. See Installing mods.
• Manifest (mod.json). The JSON file at the root of every .t3mod package: id, version, author, what it needs and conflicts with. The launcher goes by this, not by the file's name. See Mod packages.
• Map Studio. The launcher's page for exporting a map to Godot, editing it there, and repacking, installing or restoring it in the game. See The launcher: screens.
• Matching decompilation. Rewriting T3Main.exe's functions as C++ that its original compiler turns into the same machine code, byte for byte. Public, unlike raw decompiler output. See Decomp handbook.
• Mod index. The list of published mods the launcher's mod browser reads, built from this repository's modindex/ folder. It only lists mods; it doesn't host them. See Publishing to the mod index.
• Mod profile. A saved set of mods — which ones are on, and in what order — that you can switch to in one step, for example a "Vanilla" profile with everything off. See Installing mods.
• Sneaky Upgrade. A popular third-party patch for this game, distributed separately from T3SDK. Its Direct3D wrappers and texture/material override folders coexist with T3SDK; see Other mods and tools.
• symbols.txt. This project's name database (config/PC_20040610/symbols.txt): every identified function and global, by address. See Decomp handbook: naming.
• T3Ed. Ion Storm's own level editor for the game, released publicly in February 2005. Maps built from scratch still need it; T3SDK's own map editor only edits what's already in a map. See Map editing and Assets and formats.
• T3SDK.ini. T3SDK's own settings file, next to dinput8.dll in the game's System folder. Edit it directly, or use the launcher's SDK settings page. See Settings explained.
• .t3mod. The file every mod ships as: a zip with a mod.json manifest at its root, holding code, content, or both. See Mod packages.
• .t3u. A script package, System/*.t3u: compiled UnrealScript, and for T3Gamesys.t3u, the archetypes too. Unreal's own package format, like .gmp (above). See Assets and formats.
• Texture pack. A content mod that replaces textures, either through Sneaky Upgrade's override folders or, experimentally, written straight into the game's .ibt bundles (above). See Installing mods.
• TimeManager. Ion Storm's own game clock: a singleton that brackets every frame and produces its game-time delta. Its 10 ms minimum step is what SmoothFrames changes. See Game and engine: runtime and Settings explained.
• UnrealScript. Unreal Engine's own scripting language. The game's classes and archetypes are written in it and shipped compiled, inside .t3u packages (above). See Game and engine: objects.
• Unsupported build. Any T3Main.exe that isn't the exact Steam patch 1.1 build T3SDK checks for. T3SDK detects it, changes nothing, and lets the game run exactly as it would without T3SDK. See Unsupported builds.
• VSync (VSynch). The game's own Options > Audio/Video setting that paces frames to the monitor's refresh rate. In T3SDK's borderless window it now works there too, except together with MultiSampling. See Settings explained.
• WidescreenUI. The T3SDK fix that lays menus and the HUD out for the screen's own aspect ratio instead of stretching a 4:3 layout to fill it. See Settings explained.