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Configuring 1.13

One of the best things about 1.13 is how much of the game is externalized into plain-text configuration files. Almost everything — from screen resolution to enemy drop rates to how much a helicopter repair costs — can be changed with a text editor. This page is the map: which file lives where, what it controls, how the Data folders stack on top of each other, and how to edit everything without breaking your install.

Don't use the bundled INI Editor

Your game folder contains an INI Editor.exe. Long-standing community advice is to not use it — it is known to cause problems. Edit INI and XML files with a plain text editor instead, such as Notepad++. The Tools page explains why: the editor's setting schema is out of date, and saving with it can silently reset settings it doesn't know about.

Playing a mod instead of plain 1.13?

Wherever this documentation says Data-1.13, substitute the data folder of the mod you are playing — for example Data-AIM for AIMNAS. See How the Data folders stack below.

The configuration files at a glance

File Location What it controls
Ja2.ini game root (next to ja2.exe) Engine-level settings: resolution, windowed mode, which game mode (VFS config) to load, tooltip scaling, intro playback, INI merging
Ja2_Options.INI Data-1.13 The big one — the bulk of 1.13's gameplay settings
CTHConstants.ini Data-1.13 Tuning for the New Chance to Hit (NCTH) system
APBPConstants.ini Data-1.13 Action Point (AP) and Breath Point (BP) costs and tuning
Various *_Settings.ini and other INIs Data-1.13 Per-subsystem settings: morale, skills, taunts, helicopter, and more
XML files Data-1.13\TableData Game data: items, weapons, merc profiles, difficulty presets, vehicles…
vfs_config.*.ini game root Definitions of the four playable modes (advanced; usually left alone)

Ja2.ini — resolution, window mode, game mode

Ja2.ini sits in the game root next to ja2.exe and holds the settings the engine needs before any game data is loaded. Everything lives in one [Ja2 Settings] section, and every key is explained by comments in the file itself. The ones you are most likely to touch:

Setting What it does
SCREEN_RESOLUTION Picks the game resolution from a numbered list in the file — 0 is the original 640×480, 8 is 1366×768 (the default), 20 is 1920×1080, up to 24 for 2560×1600. 25 means custom.
CUSTOM_SCREEN_RESOLUTION_X / CUSTOM_SCREEN_RESOLUTION_Y Your own resolution, used only when SCREEN_RESOLUTION = 25.
EDITOR_SCREEN_RESOLUTION Same list, but for the Map Editor.
SCREEN_MODE_WINDOWED 0 = full screen, 1 = windowed.
VFS_CONFIG_INI Which game mode to launch — see below.
TOOLTIP_SCALE_FACTOR Scales all in-game tooltip text; 100 is baseline, 200 doubles the font size. Useful at high resolutions.
PLAY_INTRO Whether the intro plays when starting a new game.
MERGE_INI_FILES Lets your personal settings survive updates — see Keeping your changes across updates.

Display problems?

The comment next to SCREEN_MODE_WINDOWED about switching Windows to 16-bit color predates modern installs, which ship the cnc-ddraw wrapper to handle display compatibility. If the game looks wrong or won't display, see Troubleshooting before editing color-depth settings by hand.

The four playable modes

A 1.13 install can launch four different games. VFS_CONFIG_INI in Ja2.ini selects which one by pointing at one of the four config files shipped in the game root:

; JA2 1.13
VFS_CONFIG_INI = vfs_config.JA2113.ini

; JA2 1.13 - Vanilla (JA2 Classic)
; VFS_CONFIG_INI = vfs_config.JA2Vanilla.ini

; JA2 Unfinished Business 1.13
; VFS_CONFIG_INI = vfs_config.UB113.ini

; JA2 Unfinished Business 1.13 - Vanilla (JA2UB Classic)
; VFS_CONFIG_INI = vfs_config.UBVanilla.ini

Only one line may be active; the others stay commented out with ;. Mods that ship their own data folder usually come with their own vfs_config.XYZ.ini — switching to the mod is the same one-line change.

Ja2_Options.INI — the big one

Data-1.13\Ja2_Options.INI is where the vast majority of 1.13's switches live: difficulty tweaks, economy, enemy behavior, item drops, squad sizes, and much more, organized into commented sections. Since r8610 it also holds a number of options that used to be on the New Game screen (see New game options).

CTHConstants.ini — NCTH tuning

Data-1.13\CTHConstants.ini controls the New Chance to Hit system and the shooting mechanics behind it. Most of its values are multipliers that set how strongly each factor — marksmanship, wounds, aiming, and so on — influences your chance to hit. It only matters if you play with NCTH enabled; see New Chance to Hit for what the system does and whether you want it.

APBPConstants.ini — action and breath points

Data-1.13\APBPConstants.ini holds the constants for the Action Point (AP) and Breath Point (BP) system: how many APs a turn gives and what actions cost. Per the file's own instructions, if you want a different AP scale you change the AP_MAXIMUM property; all other AP values in the file stay expressed on the 100-AP scale and are adjusted dynamically in game.

The other INIs in Data-1.13

Each subsystem INI in Data-1.13 documents its own settings with inline comments — open one in a text editor and read before changing anything. In a current install you will find:

File What it covers
AI.ini Configuration for the modular tactical AI ("plan factories" assigned per AI index)
Creatures_Settings.INI Sector coordinates used by the creature quest
Helicopter_Settings.INI Helicopter settings such as repair costs and repair times
IntroVideos.ini Which video files play as intros, and how to replace or disable them
Item_Settings.ini Global modifiers for item properties (weight, armor, range, damage, AP to fire…) applied on top of the item XMLs
Mod_Settings.ini Sector coordinates for otherwise hardcoded locations (rebel hideout, strategic AI spawn sector) — mainly relevant to map mods
Morale_Settings.INI Morale gains and losses for tactical and strategic events
RebelCommand_Settings.ini The Rebel Command feature: supply income modifier, maximum town loyalty per difficulty
Reputation_Settings.INI How your employer reputation rises and falls
Skills_Settings.INI Trait settings — most only apply to games started with the New Trait System
Taunts_Settings.INI Enemy taunts: censoring, popup boxes, log display, whether taunts count as noise

Data-1.13 also contains a Scripts folder with the game's Lua scripts — see Lua scripting.

XML data in TableData

INI files hold settings; the XML files in Data-1.13\TableData hold the game's data: every item and weapon (in the Items subfolder, e.g. Items\Weapons.xml), merc profiles (MercProfiles.xml), difficulty presets (DifficultySettings.xml — starting cash lives here), vehicles (Vehicles.xml), and much more. Editing them is just as approachable as the INIs, but the files are less self-documenting, so read XML files first — it also covers the XML Editor tool.

How the Data folders stack

1.13 uses a Virtual File System (VFS): when the game needs a file, it searches a stack of layers from top to bottom and uses the first copy it finds. In the standard 1.13 mode the stack looks like this, top first:

  1. Your user profile — Profiles\UserProfile_JA2113. The only writable layer: savegames, temporary files and (optionally) your personal INI overrides live here.
  2. Data-1.13 — everything the 1.13 mod adds or replaces.
  3. Data — the loose files from your original JA2 installation.
  4. The vanilla SLF archives (Anims.slf, Tilesets.slf, …) inside Data — the original game's packed assets.

So a file in Data-1.13 always wins over the same file in Data, which wins over the archives. That is the whole trick behind 1.13 modding: a mod is just another layer. Mods ship their own folder (Data-AIM for AIMNAS, and so on) plus a vfs_config file that inserts it into the stack — usually on top of Data-1.13, so the mod's files win where they exist and 1.13's files fill the gaps. That's also why this documentation says "substitute your mod's folder for Data-1.13": from your point of view as a player, the topmost data folder is where the effective configuration lives.

Each playable mode also gets its own user profile folder under Profiles (UserProfile_JA2113, UserProfile_JA2Vanilla, UserProfile_UnfinishedBusiness), so savegames from different modes never mix.

The exact stack for each of the four playable modes is defined in the vfs_config.*.ini files in the game root. You normally never edit these; if you want to build your own mod layer or understand the syntax, see the Virtual File System and how 1.13 modding works.

Editing safely

  • Use a plain text editor — Notepad++ or similar. Not the bundled INI Editor, and not a word processor.
  • Back up before you edit. Copy the file (e.g. Ja2_Options.INI → Ja2_Options.INI.bak) so you can always get back to a known-good state. Keeping a backup copy of your whole game folder is even better.
  • Change one thing at a time, then test in game. If something breaks, you know exactly which edit caused it.
  • Read the comments. Nearly every INI setting is documented right above the line you are changing, including its valid range.
  • Some settings only take effect on a new game — the inline comments usually say so (for example, the trait settings in Skills_Settings.INI only apply to campaigns started with the New Trait System).

Keeping your changes across updates

Updating 1.13 overwrites the INI files in Data-1.13, taking your carefully tuned settings with it. The engine has a fix for this: INI merging.

Ja2.ini ships with:

MERGE_INI_FILES = Ja2_Options.INI

For every file named in this comma-separated list, you can place a personal copy in your user profile folder (Profiles\UserProfile_JA2113 for the standard 1.13 mode). That copy only needs to contain the settings you changed, each under its original [section] header — not the whole file. At load time the game reads the base file from Data-1.13 and then overwrites those values with yours.

For example, a minimal Profiles\UserProfile_JA2113\Ja2_Options.INI that just disables the Drassen counterattack:

[Strategic Event Settings]
TRIGGER_MASSIVE_ENEMY_COUNTERATTACK_AT_DRASSEN = FALSE

Now updates can replace Data-1.13\Ja2_Options.INI freely — your overrides in the profile folder survive untouched. To merge additional INI files, add their names to the MERGE_INI_FILES list.

Note

Check the section name in your current Data-1.13\Ja2_Options.INI when writing an override — a key must appear under the same [section] header it has in the base file.

Going deeper

Sources

  • Ja2.ini, vfs_config.JA2113.ini, APBPConstants.ini, CTHConstants.ini, AI.ini, Item_Settings.ini, Mod_Settings.ini, Skills_Settings.INI, Morale_Settings.INI, RebelCommand_Settings.ini, Reputation_Settings.INI, Taunts_Settings.INI, Creatures_Settings.INI, Helicopter_Settings.INI, IntroVideos.ini and Ja2_Options.INI from the current game directory repository, github.com/1dot13/gamedir (fetched July 2026)
  • File listings of the gamedir repository root, Data-1.13, Data-1.13/TableData, Data-1.13/Scripts and Profiles via the GitHub API (fetched July 2026)
  • VirtualFileSystem_Setup.txt v1.1 by BirdFlu, from the 1.13 SVN repository
  • INI merging note (MERGE_INI_FILES), from the 1.13 SVN-era documentation
  • Jagged Alliance 2 v1.13 Starter Documentation (r8741-era), sections "Configuration" and "Recommended Settings"