OpenCiv3

OpenCiv3 is a free, open-source fan remake of Civilization 3 built with the Godot Engine and C# under the MIT license; it is in pre-alpha, its latest release is v0.3 "Dutch" Preview 1 (December 2025), and it runs on 64-bit Windows, Linux and macOS, using a Civ 3 Conquests or Complete install for its graphics or placeholder art without one.

OpenCiv3 is a fan-made, open-source remake of Civilization 3: its official site calls it "an open-source, cross-platform, mod-oriented, modernized reimagining" of the game, built with the Godot Engine and C# and released under the MIT license. It is in "an early pre-alpha state", and its latest release is v0.3 "Dutch" Preview 1, announced for December 2025 and published on GitHub on Dec 7, 2025. It runs on 64-bit Windows, Linux and macOS and borrows its graphics from a Civ 3 install if you have one. It is a fan project, not a Firaxis or 2K product.

Quick facts

What it is	Fan remake of Civilization 3, open source
Engine	Godot, written in C# (and Lua, per its README)
License	MIT
Status	Pre-alpha
Latest release	v0.3 "Dutch" Preview 1, Dec 7, 2025
Earlier milestones	v0.0 "Aztec" (Nov 2021), v0.1 "Babylon" (Mar 2022), v0.2 "Carthage" (Jan 2025)
Platforms	64-bit Windows, Linux, macOS
Civ 3 files	Optional: reads a Conquests or Complete install for graphics
Former codename	C7
Development	Active: last change merged Oct 20, 2026, 126 pull requests merged since Dutch Preview 1
Price	Free

Source: openciv3.org, GitHub: C7-Game/OpenCiv3 and its releases, read Oct 22, 2026.

What OpenCiv3 is

OpenCiv3 rebuilds Civilization 3 from scratch with modern tools rather than changing the original program. Its GitHub README describes "an open-source, mod-oriented remake of Civilization III by the fan community", aiming at a game that looks and plays like Civ 3, and the site says it means to do away with the original's arbitrary limits. The project was "formerly known by the codename "C7"", which is why its GitHub organization is C7-Game; its repository there dates from Feb 25, 2021.

It is a different kind of project from C3X, which modifies the Conquests program that Steam and GOG sell. OpenCiv3 is its own program and does not need the original game to run.

What you need to play it

OpenCiv3 runs on 64-bit Windows, Linux and macOS, and the site says other platforms "may be supported in future releases". It recommends a local install of Civ 3 from Conquests or the Complete edition, which it uses for graphics; the original game does not have to run on your computer. Without one, a "Standalone mode" uses placeholder graphics.

The site's install steps are short. On Windows, download the release's zip, extract it and run OpenCiv3.exe (unblocking it first if Windows asks). On Linux and macOS, OpenCiv3 finds the Civ 3 files through the CIV3_HOME environment variable; on Windows it can also read the install's location from the registry. On macOS, the site warns that Gatekeeper may call the app damaged and gives a command to clear that flag. For buying and installing the original game, see Running Civilization 3 Today.

How far along it is

OpenCiv3 is playable but far from complete. Its README calls it "a rudimentary playable game but lacking many mechanics and late-game content, and errors are likely", and the site says it still uses many primitive placeholder assets. Reading the original game's BIQ rules files and SAV saves is incomplete: some fail to load and crashes may happen. On macOS, the site lists a crash when starting a new game in Dutch Preview 1, with loading a bundled save as the workaround.

Its milestones so far are named after civilizations, in alphabetical order. Its GitHub releases run from the "Aztec" milestone v0.0 (Nov 29, 2021) and "Babylon" v0.1 (Mar 23, 2022), through four "Carthage" previews in 2022 and the v0.2 "Carthage" release (Jan 5, 2025), to v0.3 "Dutch" Preview 1 (Dec 7, 2025), which the site calls a major step up from Carthage. The site gives no date for the next milestone.

Each release added a layer. The v0.2 "Carthage" release moved the project to Godot 4 and .NET, gave it a default map with Carthage, a starting Settler and Worker, custom city graphics and "limited support for loading Civ3 saves and scenarios"; the Carthage previews of 2022 had added combat details such as defensive bombard, retreat odds, terrain and river defense bonuses, healing and experience levels, production from real tile yields, roads and an AI that clears nearby barbarian camps. Dutch Preview 1 was, in the team's words, "our debut with standalone mode", the first version that plays with placeholder graphics and no Civ 3 files at all. Release notes and discussion for each version are on CivFanatics, such as the Dutch Preview 1 thread.

Is it still being developed?

Yes. The project has had no release since Dec 7, 2025, but work has not stopped: by GitHub's records, read on Oct 22, 2026, 126 pull requests have been merged since Dutch Preview 1 and the latest went in on Oct 20, 2026, a change that remembers whether the map grid is shown. The repository has 33 listed contributors and about 670 stars, and it is mostly C#. New work appears on GitHub first and reaches players only in the next release, so the downloadable game is still Dutch Preview 1.

Modding and contributing

OpenCiv3 is built to be modded: "mod-oriented" is in its own description, and its README lists QueryCiv3, "a data reader for Civ3 BIQ and SAV files", among its parts, the same BIQ files the original editor writes (see Editor and Modding). Anyone may read, change and share the code under the MIT license. The site points contributors to a CivFanatics subforum, a Discord server and the GitHub repository.

Frequently asked questions

What is OpenCiv3? OpenCiv3 is a free, open-source fan remake of Civilization 3 built with the Godot Engine and C#, under the MIT license, in pre-alpha as of its v0.3 "Dutch" Preview 1 of December 2025 (openciv3.org).

Is there a Civ 3 remake? Not an official one: no remaster of Civilization 3 has been announced by Firaxis or 2K, but the fan project OpenCiv3 is remaking it as open-source software, playable in pre-alpha (openciv3.org).

Do I need Civilization 3 to play OpenCiv3? No: OpenCiv3 has a standalone mode with placeholder graphics, but its site recommends a Civilization 3 Conquests or Complete install, which it reads for the original graphics.

Does OpenCiv3 run on Mac and Linux? Yes: OpenCiv3 runs on 64-bit Windows, Linux and macOS, and the original Civilization 3 does not have to run on that computer (openciv3.org).

Is OpenCiv3 still being worked on? Yes: OpenCiv3's GitHub repository had changes merged as recently as Oct 20, 2026, and 126 pull requests since its last release, v0.3 "Dutch" Preview 1 of Dec 7, 2025 (GitHub, read Oct 22, 2026).

Is OpenCiv3 finished? No: OpenCiv3 is in pre-alpha, "lacking many mechanics and late-game content", by its README, and its loading of Civilization 3 rules and save files is incomplete.