Desync debugging
OpenTTD Development Documentation
External Links

OpenTTD GitHub
Contributing to OpenTTD - guidelines
OpenTTD Doxygen

General Reference

Coding style
Compiling OpenTTD
Add a setting
Add a squirrel function
Understanding the SaveGame handler
Bumping the savegame version
Doing an OpenTTD release

Language and Strings

Manual of style
Format of langfiles
Using OpenTTD strings
List of special strings

Window System

Using the window system
Colour codes that exist in OpenTTD
Adding a text box
Understanding the widget focus system
GUI style guide


The OpenTTD TCP protocol
The OpenTTD UDP protocol
Debugging desyncs
Server Admin Port development

Ingame Console

The console window
Console commands
Console variables
Using console scripting
Adding functions/commands to the console
Adding variables to the console
Console development history

Content APIs (modding frameworks)

Graphics and similar (NewGRF)
AI framework (NoAI)
GameScript framework (NoGO)
Social Integration

Other Reference

Map array (landscape grid)
Train acceleration
Sound IDs


OpenTTD GitHub docs contain a guide to desyncs.

How to gather desync data

In order to fix a desync, one needs playback data. Only server admins can gather the data and their help is needed as they need to enable desync debugging on their servers. Without these desync debugging data, one has nearly no chance to find and fix these bugs. This is how you can gather the necessary data and help us pinpoint and ultimately fix the problem:

Anything less will likely not fix the desync issue nor help finding it. Thus, if you are a server admin and want to see them gone, enable desync debugging on your server and gather the data! Don't wait for anyone else - chances are slim there will be, especially as some desyncs might need the specific combination of settings and / or NewGRFs which only you use on a server.