Getting Started

Community-reported

Distilled from the OpenWorldGames (OWG) forum, board "Single player modding" (~81 threads, active 2011–2017, some still get replies today) — the successor to the original Something Awful thread where Gibbed first published his tools — plus Discord exports from two active servers, "Far Cry 2 Multiplayer" and "Far Cry Modding Community". Not independently verified by reverse engineering; treated as the most probable explanation where it hasn't been RE-confirmed. See the intro for how RE-verified and community-reported claims are distinguished across this site. Discord-sourced facts are tagged inline as (Discord, <server>, "<channel/thread>").

Mod-specific downloads are tracked in Mods Survey; tools and communities in Sources. Concrete gameplay-tuning recipes are on Data Recipes. Known unresolved problems are on Gotchas, and engine architecture theory plus the map editor are on Engine Theory. If you'd rather use a mod manager than hand-edit patch.dat, see Vortex for the tooling built in this repo.

The modding model

There is no loose-file override and no plugin system. The engine reads every asset out of packed .dat/.fat archives, and the only one a mod may touch is Data_Win32\patch.dat/patch.fat. "Installing a mod" means recompiling that one archive pair. This is possible because an official Ubisoft patch added patch.fat\generated\entitylibrarypatchoverride.fcb specifically so any entity in any other .fcb could be overridden without touching the (huge) originals — this override hook is the mechanism every mod, and every modding tool, ultimately exploits.

Because there's no load order or compatibility layer, combining two independently-built mods means manually merging their underlying XML edits into one patch (this is exactly the gap Far Cry 2 Universal Patcher was later built to address). No official SDK was ever released — every tool covered here is fan-built reverse engineering.

Toolchain

• Gibbed's tools (Rick "Gibbed"): Gibbed.Dunia.ArchiveViewer.exe (view/extract .fat/.dat), Gibbed.Dunia.ConvertBinary.exe (.fcb ⇄ .xml), Gibbed.Dunia.ConvertXml.exe (.rml/some .xml ⇄ .xml), Gibbed.Dunia.Pack.exe, Gibbed.Dunia.Unpack.exe. Free to redistribute/modify without claiming it as your own; credit appreciated.

• wobatt's "Far Cry 2 XML File Decoder" (Delphi, needs MIDAS.DLL) sits on top of Gibbed's tools and resolves far more of the hash-only names Gibbed's raw output leaves undecoded, plus bundles a fixed copy of Gibbed's own tools (corrects a bug where XML→FCB→XML round-trips injected spurious nested <rml> elements, and one where the "no art" extraction option defaulted to true). This should be the default starting point over raw Gibbed tools:

  Metric	Original Gibbed	wobatt modified
  Files identified	88,284 (55%)	155,514 (97%)
  Object names	1,562	2,120
  Value names	499	2,493

• Bootstrap package: extract into Far Cry 2\modding, run bootstrap.bat, edit XML under modding\mymod\..., run build_patch.bat to produce patch.fat/patch.dat, copy into Data_Win32 (back up the originals first). This superseded an older manual process, still described in some guides: mirror the original folder path for any file you want to override under modding\mypatch instead (e.g. modding\mypatch\engine\gamemodes\gamemodesconfig.xml), run build_patch.bat, then rename your existing archive files' extensions (e.g. to .steamdat/.steamfat) before copying the new pair in, so the game won't load the originals.

Round-tripping .fcb values by hand

Every converted <field> looks like <field hash="ABDC41FE" name="fMaxHealth" value-Float32="1000" type="BinHex">00007A44</field> (confirmed by fcmodding.com's independent FCBConverter docs) — hash is the field name's CRC32, name the decoded readable name (either can be omitted, but one is required to convert back), value-FLOATTYPE="…" is a decoded display convenience ignored on the round-trip to binary, and type/the raw hex body is what actually gets written. To hand-edit a value without doing hex math, replace type with the real type and write the human value directly: <field hash="ABDC41FE" name="fMaxHealth" type="Float32">1000</field>. Full type list: Int16/32/64, UInt16/32/64, Float32/64, Vector2/3/4 (comma-separated floats), String, Enum, Hash32/64, Id32/64, ComputeHash32/64 (auto-hashes the given value), Boolean, BinHex (the default, raw hex). ConvertBinary gives no line numbers on malformed XML, just a raw stack trace — re-run after every small edit to isolate mistakes. A decimal-locale gotcha: a comma instead of a period in a float (1,5 instead of 1.5) is silently misinterpreted or crashes the build.

Common failures

• Bootstrap/build_patch failing silently or with permission errors almost always traces to the game being installed under Program Files (x86) without write access for a non-admin user — grant the FC2 folder write access rather than "running as administrator" (confirmed root cause by Gibbed).
• Retail (non-Steam) vs Steam builds differ, even at the same reported patch version. Installing the official v1.03 patch on a retail/GOG/Fortune's Edition copy is not sufficient — bootstrap can still fail with "Your patch.fat file doesn't seem to have generated\entitylibrarypatchoverride.fcb in it." Root cause: DVD and GOG copies are genuinely missing the patched entitylibrary data from their patchfile, even though both nominally report version 1.03 like Steam/UPlay (the DLL's DRM-check version string was patched, but not all of the actual 1.03 content files were included). Steam and UPlay share the same, fully-patched patchfile; DVD/GOG do not. Fix: substitute a known-good Steam-derived patch.fat (and, if crashes persist, a matching Dunia.dll + patch.dat/patch.fat triplet) in place of the retail one. Forcing a Steam patch onto a retail install can introduce minor UI glitches (garbled "W" characters in the main menu — a Ubisoft news-feed widget breaking, fixable but must be redone per display language — plus a crash on quit) as a side effect. The actual content difference in the missing .Multi-variant overrides is mostly minor fixups and MP balance changes; the only real singleplayer-relevant gap is negligible, so this mostly doesn't matter outside multiplayer.
• DLC weapon data is locked: Data_Win32\downloadablecontent\dlc_1\entitylibrary.fcb cannot be decompiled by ConvertBinary at all — a hard tooling gap. The confirmed workaround (modder stoatoats, author of "RealMod"): edit the raw file directly with a hex editor, bypassing the FCB↔XML pipeline entirely. Used to change crossbow bolt gravity/speed and shotgun pellet count.
• Non-weapon DLC entity data does have a working recipe (confirmed step-by-step by wobatt): extract Known\downloadcontent\dlc1\generated\entitylibrary.fcb from Data_Win32\downloadcontent\dlc1\entitylibrary.fat via ArchiveViewer, rename to dlc1.fcb, convert via Gibbed.Dunia.ConvertBinary.exe --xml .\libraries\dlc1.fcb, copy the resulting dlc1_converted.xml/folder into mymod, create mypatch\downloadcontent\dlc1\generated\, and add a convert step and a copy step to build_patch.bat before the "Creating patch.fat/dat..." line. Exposes 1_DLC1Weapons.xml, 2_vehicle.xml, 3_WeaponProperties.xml for editing. Modifying 2_vehicle.xml this way guarantees a crash whenever a DLC vehicle (Unimog, Quad) spawns near your changes (reproducible near Petro Sahel) — drop the vehicle file from your DLC mod and keep only the weapon edits, which do work via this path.
• FCBConverter's CRC32 hash-collision problem, root-caused live by its own author (Discord, Far Cry Modding Community, 🔨-fc2-modding, Jun 2021 — ArmanIII and Steve64b): FC2 hashes filenames with CRC32 (unlike FC3+'s CRC64), so cross-game master filelists risk real collisions — e.g. 4A724578 maps to both levels\ige_map\generated\sdat\sd10_shadow.xbt and scripts\game\barkdata\1436645.bank within FC2's own filelist. FCBConverter's loader silently keeps whichever entry appears first and drops the rest. Fix: maintain separate, per-game filelists rather than one shared master list. The same session found and fixed a related bug: single-file extraction (FCBConverter <fat> <output dir> <desired file>) wasn't passing the detected FAT version through for FC2 specifically, silently unpacking the entire fat instead of the requested file. Separately, the output-directory argument must be an absolute path — a relative path fails Directory.Exists() silently.
• A worldsector .fcb carries its own internal ID + grid coordinates, confirmed from a real hash lookup: worlds.fat\levels\mp_10_l_fishingvillage\generated\worldsectors\worldsector23.data.fcb resolves to WorldSector: Id=23 X=3 Y=2.
• .xbg mesh files can embed their own texture/material references, extractable without hex editing (Discord, Far Cry 2 Multiplayer, tools-and-mods, Feb 2026, tool by fdx4061): a standalone EXTRACTOR.exe, placed alongside a batch of .xbg files, generates a PATH.ini on first run (edit it to point at your unpacked resource directories — only the first non-commented line is used), then on a second run extracts every referenced texture/material into subfolders mirroring the original directory structure.
• Far-Cry-2-Multi-Fixer (GitHub, FoxAhead) launches the game with various fixes without modifying the executable files — confirmed to resolve a "Dll not loaded" crash. A separate, GUI-launcher-style tool from FC2MPPatcher (see Sources).

Manually merging two mods

Before Far Cry 2 Universal Patcher existed, two techniques were used:

• Fine-grained (wobatt): extract both mods' XML into separate folders, then use WinMerge to line-by-line diff the two folders against each other and manually reconcile differences.
• Coarse-grained (Discord, 🔨-fc2-modding, 2026-07-20/22, "Yorzar"): install one overhaul mod normally, unpack both mods' patch archives, then copy whole top-level folders from the second mod's unpacked tree over the first's (_UNKNOWN, databases, domino, downloadedcontent, selected graphics subfolders, levels, Scripts, Ui, Worlds), then repack. Faster than a real line-by-line merge when the two mods don't touch the same files, but whole folders win outright rather than reconciling individual field changes.

Key files & what lives where

For a full categorized survey of the install directory by file type, see File Manifest. This table covers the specific gameplay-tuning files worth knowing by name:

File / path	Contents
patch.fat\generated\entitylibrarypatchoverride.fcb	The official override hook every mod exploits (see above).
worlds.fat\world{1,2}\generated\entitylibrary{,_full}.fcb	Per-map (Leboa/Bowa) entity definitions. Load-order gotcha: despite the "full" name suggesting primacy, the game loads entitylibrary_full.fcb first and entitylibrary.fcb second in client/singleplayer mode — so entitylibrary.fcb wins on any overlapping entity. Put your edits there. World2 is a near-fully duplicated structure from world1, not shared/parameterized.
modding\libraries\world1\30_player.xml	Player + all buddy-character definitions (~11MB — every buddy gets a full duplicated rule set). Contains SensorySystem/FOVParameters (per-biome detection FOV), movement speed values, fJumpHeight, fGravity. Also reachable via patch\worlds\tmpla\generated\entitylibrary.fcb (a shared "template" world folder, distinct from world1/world2).
modding\mypatch\engine\gamemodes\gamemodesconfig.xml	Only exists after the tool's first run (or copied manually from original\patch\engine\gamemodes\). ~500KB. The arms-dealer list, per-weapon <Summary> stat blocks (cosmetic-only, pause-menu UI — not the real combat math), enemy weapon-loadout tables, mission diamond rewards, grenade-drop chance, fall-damage/health/reliability rating tables, infamy bands, the bandolier/max-ammo table, the three manual-bonus systems, faction territory data, patrol faction assignments, and vestigial cut content (a disabled pre-release Watch gadget that does nothing when re-enabled). See Data Recipes for specifics.
libraries/world1/41_WeaponProperties.xml (+ 42_weapons.xml)	The real master weapon-properties file. Fire mode, pellet count, spread, hit-location severity, damage tier, jam mechanics, scope zoom, and (via unnamed hashes) magazine size/max ammo — see Data Recipes. Each weapon typically has multiple named copies (.Multi for multiplayer, an unsuffixed singleplayer variant, sometimes .AI/.Persistent/story-specific variants) — editing the wrong copy is a common silent-failure cause.
libraries/world1/weaponpreferences.xml	DLC weapons' non-FCB preferences — core DLC weapon stats are in the separately-locked entitylibrary.fcb, not here.
09_gadgets.xml (under world1/world2)	Per-gadget max-ammo settings (grenades, molotovs) — editable directly instead of via the bandolier system.
28_pickups.xml (under world1)	World pickup definitions — small ammo/explosive/fuel pickups and named unique pickups like the Golden AK47.
curves.xml	Named curves referenced by value elsewhere (e.g. Curves.PlayerSicknessCurves.MalariaTimeBeforeFirstAttack, Curves.Locomotion.Sprint) — malaria timers, stamina/sprint curves, and max health.
world.fat\domino\system\reinforcementregion.lua, spawnreinforcement.lua	Real Lua scripts controlling checkpoint/guard-post reinforcement spawning — see Gotchas for whether patched Lua is honored at runtime.
worlds.fat\worlds\world1\generated\world1.mapdata.fcb	Patrol vehicle routes, raw XYZ coordinates with no in-game reference frame — editing routes is "hours of trial and error" without dedicated tooling.
10_Ghostpatrols.xml	Every patrol type's faction-color assignment plus optional vehicle passenger slots — see Data Recipes's faction-infighting recipe.
*.sdat (per-world-sector terrain)	See the .sdat format page.
Vehicle files (Vehicles_world1.xml)	Vehicle model/mounting data. The hang glider's flight parameters were never found despite extensive searching. A Chassis-section fHealth value exists for ground vehicles, but recompiling a patch that changes it reliably crashes the game — unresolved, suspected DLC-folder conflict.

Locally preserved reference files (research/reference-files/)

Primary-source material mined from Discord exports, worth keeping independently of the (disposable, since-deleted) raw export:

• tools/third-party/FC2Editor_Source/ — genuine, working C# source for the stock map editor (422 entries, half a byte-identical Backup/ duplicate). Built on a custom "Nomad" engine layer (FC2Editor.Nomad: Camera, Engine, Render, EditorObject/EditorObjectSelection, Gizmo/GizmoHelper, TerrainManager/TerrainManipulator, TextureManipulator, SplineManager/SplineRoad/SplineZone, UndoManager, Validation, CollectionManager/CollectionManipulator) plus a typed FC2Editor.Parameters UI-binding framework (ParamBool, ParamFloat, ParamEnum<T>, ParamButton, ParamPickButton). Confirmed genuine (not a community equivalent) via AssemblyInfo.cs's Ubisoft 2008 copyright and its ~338 Dunia.dll P/Invoke declarations matching named exports in the Ghidra project — see the editor API surface, built directly from this source.
• hash-lists/ — community-maintained CRC32→filename lookup lists: worlds.filelist (+ two earlier revisions), worlds_english.filelist, entitylibrary.filelist, dlc1.filelist, dlc_jungle.filelist, patch.filelist, map_files.filelist, and two early general-purpose master_file_v1/v2.list files.
• format-samples/ — real, working instances of documented formats: ak47.xbg/computer.xbg (mesh), 4× .xbt texture samples, decoded FCB→XML data (25_buddies.xml/world1.xml/2× soundpoint.xml), real engine Lua scripts (master_world1.world1.lua/master_world2.world2.lua/ common_hq_doorman...lua), a real archive pair (patch.dat+patch.fat), movemgrnamed.bin, a navmesh (nv_4979.nvm), a .sbao sample, a worked prefab-manager editing example, and a worked texture-swap example.
• tool-archives/ — small tools shared as direct Discord attachments rather than on GitHub: EXTRACTOR.7z (fdx4061's .xbg texture/material extractor), XBT-Thumbnail-Provider.zip, xbmEditor1.7z (fdx4061's XBM editor), SkeleTree.zip (fdx4061's cross-game skeleton reading tool).
• text-snippets/ — CRC32_collisions.txt, Far_Cry_2_1.03_filediffs.txt (the retail/GOG patch-gap root cause), crc32_collision_examples.txt, fcbconverter_collision_repro.txt, redux_readme.txt, dunia_internal_tool_plugins_list.txt (a leaked internal Dunia build-tool plugin list — ~50 build-pipeline plugins, confirming FC2's .nvm navmesh files are built on the open-source Recast navmesh library, and that NomadDB ties directly to the FC2Editor.Nomad namespace above), cloth_shader_disasm_example.txt (a readable disassembled ps_4_0 HLSL pixel shader — shader bytecode is not opaque-packed binary).