Software Development Kit for id Tech


Welcome to the manual for Nuclide!

This is a game development kit (GDK) and development environment created by Vera Visions, L.L.C.. We want to share it with everyone to avoid duplicate effort and in the hopes that it is useful to someone else.

What this project is

The Nuclide project produces a freely available game-logic component and development platform on top of FTEQW; which is the engine we happen to use.

The general idea is that Nuclide takes care of ~90% of the code you shouldn't have to worry about.

The goal is to create a modern research base for new advancements, as well as to have a stable base with a decent API for making games.

It is targetted towards developers with a background/interest in id Technology.

It comes with a simple example game (simply referred to as 'Base') and some test maps. There's also some other, third-party example projects.

General feature overview:

  • The 'missing' SDK for engines like FTEQW
  • Support for client-side predicted movement, weaponry and vehicles
  • Documented APIs for everything you need to interface with the engine
  • APIs and Frameworks for managing updates, mods, servers, and platform specific features
  • Complete re-implementations of hundreds of entities, from GoldSrc/Source engine games
  • Entity communication via traditional one-way triggers, or our Source Engine I/O compatible system
  • Includes BotLib, a framework for multiplayer-AI that can receive game-specific overrides
  • Includes VGUILib, a re-imagining of Valve's GUI library, which can also be used for in-game surface based interfaces
  • Designed to be familar to developers coming from GoldSrc/Source
  • VR/XR aware codebase
  • All permissively licensed

1. Why might I want to use it?

You might be migrating from an engine that is no longer being licensed and don't want to learn a new engine and toolchain.

You might want to develop a game using a lot of complex and well-tested objects which might be tedious to implement on your own.

You might want to run or make modifications for a game using Nuclide and need full control over what you can do.

2. How free is Nuclide?

Everything in Nuclide is free software. The copyright terms for the game-logic are very permitting. Nuclide does not use the GPL as a point of reference in terms of license, it instead uses a ISC-like license. This means you can use, copy, modify and distribute the code and work resulting from it for any purpose.

Please read the very short 'LICENSE' document for details.

3. What are the alternatives?

Implementing systems such as prediction, complex map objects and entities on your own, from scratch - or licensing another engine such as Source that ships with its own Source SDK Base.

4. Any example projects?

  • The Wastes is a commerical game built using Nuclide.
  • FreeHL is a free-software, clean-room clone of Half-Life: Deathmatch also built using Nuclide.
  • FreeCS exists in the same vein as FreeHL, but targetting a recreation of Counter-Strike v1.5 (mod version) specifically.

Getting started

First of all, you want to be sure this is what you want to get into. If you do posess a basic knowledge of the following:

  • The C programming language
  • Debugging a native application
  • Makefiles
  • Compiling your own binaries
  • Concept of public and private APIs
  • QuakeC

Then you will have a good time. We strive to keep the codebase portable and conform to open standards wherever possible. This means that if you develop on Windows, you probably want to install something like WSL or even Cygwin to make this bearable.

Please don't ask us how to use WSL or Cygwin. We do not provide support for either. We do not develop on Windows.

This is a development kit and a development environment. This is not a game.

Actually getting started

You clone the Nuclide git repository first. There's multiple places to get it, one such place may be GitHub:

git clone

And then you can get started on building the engine and the rest of the toolchain. Alternatively, you can also move in the official FTEQW binaries into the Nuclide directory to get started without bootstrapping your own engine + QuakeC compiler.