Here is the revised article with the newer-tool disclaimer at the top, the suggested technical clarifications, and the merging precautions added. I’ve retained your original wording and structure wherever possible, without adding horizontal rules or changing unrelated content.

Revised article

Disclaimer: A newer fan made modding toolkit called Riftstone is now available for Dragon’s Dogma: Dark Arisen. It may be a better option than ARCtool for some tasks, although it is still in alpha and its in-game plugins are still being tested. This guide uses the established ARCtool workflow, which remains useful for many existing mods and tutorials. I’ve not used riftstone yet Myself.

The games files are mostly compressed into encrypted .arc files. These files can be extracted and decrypted using FluffyQuack’s ARCtool. It not only extracts them, but converts supported formats into more human-readable and editable file types. These can then be repacked into a .arc and used to mod the game files.

Prepare the tools

First we need the latest version of FluffyQuack’s ARCtool.

1. Go to FluffyQuack’s tool archive here: https://www.fluffyquack.com/tools/
2. Download ARCtool.zip or .rar.
3. Copy the .exe to an empty folder.
   1. Note it doesn’t have to be empty technically, but it helps reduce confusion and errors.
4. Go to FluffyQuack’s Nexus Mods page for ARCtool here: https://www.nexusmods.com/dragonsdogma/mods/500?tab=description.
   1. This is an older version, but has some optional files we will need, unless you want to write your own .bat files or command-line commands.
5. Copy all of the .bat files beginning with pc into our ARCtool folder from earlier.
   1. Do not copy the .exe, as it is an older version.

Alternatively, you can try Riftstone, which includes its own toolkit for archive processing and editing game data. Follow its installation instructions rather than mixing its workflow with the ARCtool instructions below.

Extracting the game files

There are two main file types you will want to edit for modding: .xfs and .tex. There are corresponding batch files with those extensions in their names. .xfs files contain game data and can be converted to XML, while .tex files are texture resources. Other file types are also present, and not all game data can be converted into XML. Decide which you want to edit before continuing.

1. Go to Steam\steamapps\common\DDDA\nativePC.
2. In this maze of folders is almost all the game’s data, much of which is packaged in .arc files. See the table below for directions.
   1. For this guide I will assume we are working on game_main.arc.
3. Copy the .arc to the same folder as ARCtool.
   1. This is optional, but saves you having to redownload part of the game every time you want an unmodded .arc.
4. Drag the .arc onto the relevant .bat file.
   1. In this example we want pc-dd-xfs-conversion.bat.
5. This will create a folder with a name matching the .arc, which contains extracted files and, for supported formats, converted XML duplicates.

Merging Mods

To merge mods, you need to know what files the authors edited within the .arc. If they edited different .arcs, you don’t need to merge those archives together. Some authors provide mergeable files or instructions.

If not, you may be able to estimate which files they touched using the database below, based on what their mod claims to alter. Treat these estimates as a starting point rather than confirmation, and check the actual files where possible.

Before merging, make a backup of the original archive and extract the target .arc. Preserve the internal directory structure when copying files, and use the appropriate conversion and repacking options for the file types involved.

1. Once the above is solved, extract the target .arc.
   1. You can use a vanilla .arc or one of the mods’ .arcs.
2. Copy the mergeable files from the mods to the correct file paths in the newly extracted folder.
3. If two mods edit the same file, compare their changes and merge them within that file if you understand its format. Otherwise, you will need to choose which version to keep.
4. Drag the extracted folder onto the relevant .bat file.
5. Copy the newly created .arc into the correct file path in the game files.
6. Test the game to make sure the changes work as expected.

Note that mods that alter the same files within an .arc cannot necessarily be merged by simply copying the files together. One version will overwrite the other unless the changes are combined manually. Mods that alter different files within the same archive can often be merged.

If you use Mod Organizer 2 with the ARCtool plugin, it can help extract conflicting archives and merge enabled mods according to their priority. This is an optional alternative to manually merging files.

Repacking to .arc

Once you have finished editing an extracted .arc folder, you can repackage the folder into a .arc by dragging it onto the relevant .bat file.

Make sure you use the appropriate conversion and compression options for the files you have edited. Keep a backup of the original archive until you have tested the repacked version in-game.

Modding the files

Each .xml is a little different and difficult to decipher. Not only is a lot of it written by non-native English speakers, but it is also written in entirely undocumented formats that use numbers to name variables. Luckily for you, the community has deciphered some key files. This research I have turned into a guide and database here.

Filename	Path	Data contained	Mod examples using this file
game_main.arc	Steam\steamapps\common\DDDA\nativePC\rom	Most stat, skill, quest, augment and item data
stk.arc			Used in Signette‘s spell pack. stk.arc may contain mage skills. Example 1, Example 2, Example 3. The exact contents should be verified.
wan.arc	Steam\steamapps\common\DDDA\nativePC\rom\wp\w1		Used in Signette‘s spell pack. Example 1, Example 2, Example 3, Example 4. wan.arc may correspond to sorcerer skills, magic or skills as a whole. These associations should be treated as tentative until verified.
bbs_rpg.arc	Steam\steamapps\common\DDDA\nativePC\rom\bbs_rpg.arc	Equipment stats, enchantments and model data	Used in this mod.
bld.arc			Magick Knight shield skills mod: Mystic Knight shield skills.
mbw.arc / mbw13.arc		Magic bow skills	Contains a commented XML: example.

Extracted Files

Inside .arc	Filename	Path within extracted .arc	Data contained	Sources
bbs_rpg.arc	itemList.itl	bbs_rpg/etc/item/itemList.itl	Armor, resistances, strength and magick bonuses, vocation equipment restrictions, model, body parts, weight, price and possibly more.	Nexus Mods forum, mod example, Reddit research
bbsrpg_core.arc	t_cm000_00_GM.241F5DEB	bbsrpg_core\effect\tex\cm\	Texture for glow effects.
bbsrpg_core.arc	t_cm040_00_GM.241F5DEB	bbsrpg_core\effect\tex\cm\	Texture for glow effects.
game_main.arc	LvTrickster.lvl		Stat gains per level for Magick Archer.
game_main.arc	LvPaladin.lvl		Stat gains per level for Mystic Knight.
game_main.arc	LvAssassin.lvl		Stat gains per level for Assassin.
game_main.arc	questReward.qr		Quest rewards, including currencies, items and possibly which NPC gives the quest.

Editing itemList.itl

Hex editor: HxD

1. Open the extracted file in a hex editor.
2. Identify which item you wish to edit (see below table).
3. Save the file and repack the .arc.

Reading the code

According to Xervous_ in this reference:

Each item’s data ends with 31 29.

Hex editor: HxD

1. Open the extracted file in a hex editor.
2. Identify which item you wish to edit (see below table).
3. Save the file and repack the .arc.

Further Reading

Knows a lot about modding NPCs and equipment: LDKSuperDante.

A well-formatted report on balance: Google Docs.

A report on a lot of the formulae involved in damage calculations and other stuff: Google Docs.

A rough model swapping guide by omnitorpor.

Info on level editing: Nexus Mods.

XP gain and/or requirements: Nexus Mods.

Enemy spawn editing tutorial: Nexus Mods.