LTX Format¶

LTX is X-Ray's custom INI-like format. It's used for almost all game data definitions — items, weapons, creatures, AI behavior, physics properties, and more. Understanding it is essential for any mod that touches stats or config values.

Basic syntax¶

; This is a comment

[section_name]
key = value
another_key = 1.5
flag = true
list_value = item_a, item_b, item_c

Sections are declared with [section_name]
Keys and values are separated by =
; begins a comment (rest of line is ignored)
Values can be strings, numbers, booleans (true/false), or comma-separated lists
Whitespace around = is ignored; trailing whitespace on values is also ignored

Section inheritance¶

A section can inherit all properties from a parent section:

[child_section]:parent_section
; Only override what differs
health = 500
speed = 2.0

The child gets every property defined in the parent. Any key defined in the child overwrites the parent's value for that key. This is how Anomaly builds its item hierarchy — most weapons inherit from a base weapon section, most food items from a consumable base, etc.

Multiple inheritance is supported:

[my_item]:base_item,identity_immunities

The engine merges all ancestor properties, resolving conflicts left-to-right.

Include directives¶

LTX files can include other LTX files. The included file's contents are merged in at that point.

#include "weapons_base.ltx"
#include "upgrades\upgrade_presets.ltx"

; Wildcards load all matching files
#include "w_*.ltx"
#include "items_*.ltx"

This is how the engine's master config files work — system.ltx includes dozens of sub-files, and configs/items/weapons/base.ltx uses #include "w_*.ltx" to load all weapon definitions automatically.

Paths in includes are relative to the file containing the directive.

Data types¶

LTX value	Lua read method	Example
String	`r_string` / `r_string_ex`	`"stalker"`, `"my_sound_file"`
Float	`r_float` / `r_float_ex`	`1.5`, `0.25`, `-10`
Integer (signed)	`r_s32`	`42`, `-1`
Integer (unsigned)	`r_u32`	`0`, `65535`
Boolean	`r_bool` / `r_bool_ex`	`true`, `false`
Comma list	`r_string` then split	`a, b, c`

Reading LTX from Lua¶

The system ini¶

system_ini() returns the engine's merged view of all loaded LTX files. It's the main way scripts access item stats, creature properties, and global settings:

local ini = system_ini()   -- or use the global alias: ini_sys

ini_sys is a cached reference to system_ini() defined in _g.script — prefer it over calling system_ini() directly in hot paths.

Read methods¶

local sec = "my_item_section"

-- Strings
local name   = ini_sys:r_string(sec, "inv_name")          -- errors if missing
local name   = ini_sys:r_string_ex(sec, "inv_name")       -- returns nil if missing

-- Numbers
local weight = ini_sys:r_float(sec, "inv_weight")
local weight = ini_sys:r_float_ex(sec, "inv_weight")      -- returns nil if missing
local cost   = ini_sys:r_u32(sec, "cost")                  -- unsigned int
local rank   = ini_sys:r_s32(sec, "min_rank")              -- signed int

-- Booleans
local usable = ini_sys:r_bool(sec, "use_condition")
local usable = ini_sys:r_bool_ex(sec, "use_condition")    -- returns nil if missing

-- Existence checks (always do this before r_string/r_float/r_bool to avoid errors)
if ini_sys:section_exist(sec) then
    -- section is present
end

if ini_sys:line_exist(sec, "special_field") then
    -- key exists in this section
end

The _ex variants return nil instead of throwing an error when the section or key is missing. Always use _ex variants unless you're certain the field must exist.

Loading a custom ini file¶

-- Load an ini file directly (path relative to gamedata/)
local my_ini = ini_file("configs\\my_mod\\settings.ltx")

local value = my_ini:r_float_ex("settings", "some_value") or 1.0

Safe read pattern¶

local function read_cfg(section, key, default)
    if not ini_sys:section_exist(section) then return default end
    if not ini_sys:line_exist(section, key) then return default end
    return ini_sys:r_string_ex(section, key) or default
end

Common LTX structure patterns¶

Item definition¶

[my_item]:booster_multi    ; inherits from booster_multi base
$spawn          = "food and drugs\my_item"
inv_name        = st_my_item
inv_name_short  = st_my_item
description     = st_my_item_descr
inv_weight      = 0.5
cost            = 300
inv_grid_x      = 5
inv_grid_y      = 12
inv_grid_width  = 1
inv_grid_height = 1
eat_health      = 0.1
boost_time      = 30

Weapon definition (abbreviated)¶

[wpn_my_pistol]:wpn_pistol_base
inv_name        = st_wpn_my_pistol
hit_power       = 0.45, 0.45, 0.45, 0.45
fire_distance   = 60
ammo_class      = ammo_9x18_fmj, ammo_9x18_pbp
rpm             = 300

Common files¶

File	Contents
`configs/system.ltx`	Master include file — loads everything else
`configs/items/items/items_*.ltx`	Consumables, artefacts, equipment
`configs/items/weapons/w_*.ltx`	Weapon definitions
`configs/creatures/m_*.ltx`	Creature / mutant definitions
`configs/creatures/monsters.ltx`	Includes all creature files
`configs/gameplay/character_desc_*.ltx`	NPC character definitions
`configs/misc/zone_*.ltx`	Anomaly zone definitions

Gotchas¶

Case sensitivity. Section names and keys are case-sensitive on some builds. Use lowercase consistently.

No spaces in section names. [my section] is invalid. Use underscores: [my_section].

Boolean values are strictly true or false. 1, yes, or on will not be parsed as booleans by r_bool.

Comma-separated lists have no fixed length. Read them as a string with r_string_ex then split on ,:

local ammo_str = ini_sys:r_string_ex("wpn_ak74", "ammo_class") or ""
local ammo_list = {}
for sec in ammo_str:gmatch("[^,%s]+") do
    ammo_list[#ammo_list + 1] = sec
end

Modding: Don't edit base game LTX files directly — use DLTX to patch only the values you need to change.