# openh4: reimplementing the Heroes of Might and Magic IV engine

> openh4 reimplements the Heroes of Might and Magic IV engine in C++23 using data from a player's own GOG copy. The repository contains the engine, a game application and h4-tool for inspecting and rendering game data. The author describes the project as unfinished.

- Type: Case study
- Targets: Game
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/tallowmere/free-heroes4>
- Primary source: <https://github.com/tallowmere/free-heroes4/blob/57d72e8b8a59e29c42bb7e34122997a2bd59d85e/README>
- Catalog page: <https://awesomerea.org/resources/openh4-case/>
- Record JSON: <https://awesomerea.org/resources/openh4-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/openh4-case/index.md)

## Requirements & limits

- **Prerequisites:** An original Heroes of Might and Magic IV copy from GOG is required.
- **Prerequisites:** Building requires CMake 3.28 or newer, Ninja, a C++23 compiler, zlib and liblzma; SDL3 is required for the game application.
- **Limits:** The project is unfinished.
- **License:** GNU General Public License version 3.

## Primary sources

1. <https://github.com/tallowmere/free-heroes4/blob/57d72e8b8a59e29c42bb7e34122997a2bd59d85e/README>
2. <https://github.com/tallowmere/free-heroes4/blob/57d72e8b8a59e29c42bb7e34122997a2bd59d85e/LICENSE>

## More in Games

- [OpenHoW: rebuilding Hogs of War from its game data](https://awesomerea.org/resources/openhow-hogs-of-war-case/index.md) · Case study
- [OpenIGI: a C# engine reimplementation for Project I.G.I. and I.G.I. 2](https://awesomerea.org/resources/openigi-engine-case/index.md) · Case study
- [OpenInsaniquarium: reimplementing Insaniquarium Deluxe](https://awesomerea.org/resources/openinsaniquarium-case/index.md) · Case study
- [OpenJazz: a Jazz Jackrabbit 1 engine reimplementation](https://awesomerea.org/resources/openjazz-case/index.md) · Case study
- [OpenJKDF2: C reimplementation of Jedi Knight: Dark Forces II](https://awesomerea.org/resources/openjkdf2/index.md) · Case study
- [OpenJones3D: reconstructing the Indiana Jones and the Infernal Machine engine](https://awesomerea.org/resources/openjones3d-case/index.md) · Case study

## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.