---
title: libraries: where X4 keeps its world rules
summary: Find the XML tables for economy, population, game starts and behavior.
section: data
kind: guide
status: reference
updated: 2026-10-27
tags: ["X4","modding","game","data","libraries"]
sources: ["https://chemodun.github.io/x4/modding-support/anatomy-of-game-data/libraries/"]
---
## Start with the task


`libraries/` holds data tables. MD consumes data and performs actions; Lua displays it in the interface. Editing a table and running a script are separate steps. This X4 9.00 map helps you choose a file to investigate first.



## File map


| What to change | Start here |
| --- | --- |
| Prices and recipes | `wares.xml` |
| Available ships and selection groups | `ships.xml`, `shipgroups.xml` |
| Station plans | `constructionplans.xml`, `stationgroups.xml` |
| Equipment compatibility | `equipmentcompatibilities.xml` |
| Drone and consumable selection | `loadoutrules.xml` |
| NPC ship replenishment | `jobs.xml` |
| Initial station placement | `god.xml` |
| Factions, races and relations | `factions.xml`, `races.xml`, `diplomacy.xml` |
| Player starting conditions | `gamestarts.xml` |
| Main-menu background scene | `startmenu.xml` |
| Resource areas | `regionyields.xml`, `mapdefaults.xml` |
| Dropped items | `drops.xml` |
| Game-system parameters | `parameters.xml` |
| Terraforming and feature unlocks | `terraforming.xml`, `unlocks.xml` |


These are search pointers, not a promise that one file is enough. A new ship, for example, connects a macro, ware, indexes and text.



## Read the file you found


Extract matching data with [X Catalog Tool](wiki:tool-catalog). Identify the document root, entry and ID. Check its schema where declared, then other tables using that ID. Some tables gather full extension files; other changes use diff patches. Choose the form for that particular file and a working analogue, not merely its directory name.



Independent exercise: outline the dependencies of a fictional patrol.



```text
wiki_patrol_job -> ship group -> ship macro
                -> default AI order
                -> quota + location
```



**Result:** a list of references to find and validate. This reasoning diagram creates no ship and prints nothing in game.



## Next steps


[NPC ships and stations](wiki:jobs-and-god), [game starts and menu backgrounds](wiki:gamestarts-and-menu), [wares and prices](wiki:wares-and-prices), [resource areas](wiki:resource-areas). The source covers `people`, `stats`, `quotas` and `missiongroups` in more detail; this wiki does not yet provide complete courses on them.