What Is Arx Fatalis and How Do You Play It With Arx Libertatis?

Arx Fatalis is a 2002 first-person role-playing game / dungeon crawler / immersive sim developed by Arkane Studios. Arx Libertatis is an improved, cross-platform, open source engine for it, based on the publicly released Arx Fatalis source code and available under the GPL 3+ license. To play Arx Fatalis through Arx Libertatis, you need two things: a copy of the original game (or its demo) for the game data, and an Arx Libertatis build for your platform. Arx Libertatis itself does not include the game data.

What Arx Fatalis actually is

Arx Fatalis is a first-person RPG set underground, built around exploration, combat, and spellcasting. Its most distinctive feature is a casting system where the player draws runes in real time to effect the desired spell. It also features crafting, melee and ranged combat.

The game was developed by Arkane Studios and released in 2002. It sits in the immersive sim / dungeon crawler space, which is why it still gets attention from players interested in that style of game.

What Arx Libertatis adds

Arx Libertatis 1.2.1 updates and improves Arx Fatalis by:

• Supporting modern systems
• Porting the game to new platforms
• Eliminating bugs and limitations of the original release

It is an engine replacement, not a remake. The stated future direction is to further improve and modernize the engine and to enable customizations and mods by the community.

Licensing, in plain terms

Arx Libertatis is based on the publicly released Arx Fatalis source code and is available under the GPL 3+ license. That license covers the engine, not the game content. The game data is not included, so you must obtain a copy of the original Arx Fatalis or its demo to play Arx Libertatis.

Which platforms are supported

Official builds are provided for Windows and Linux. Beyond that, Arx Libertatis has been packaged for:

The project notes it will likely compile and work on other operating systems as well, though those are not listed as packaged targets.

How to play Arx Fatalis with Arx Libertatis

1. Get the game data. Obtain a copy of the original Arx Fatalis or its demo. The project points to GOG.com, the Microsoft Store, and the Bethesda Store as places to get the game.
2. Download Arx Libertatis for your platform. Builds are provided for Windows and Linux from arx-libertatis.org. For macOS, use the Homebrew package; for the BSDs, Haiku, and Pandora, use the respective packaged versions.
3. Install Arx Libertatis. Run the installer or package for your platform.
4. Point Arx Libertatis at your installed game. When you run it, direct it to the directory where the original Arx Fatalis (or demo) is installed so it can read the game data.
5. Play. Once the game data is located, Arx Libertatis runs the game with its engine improvements applied.

The key constraint at every step is the same: Arx Libertatis supplies the engine, and the original game supplies the data. Neither half works alone.

Where to find the game and the project

Arx Fatalis (game data):

• GOG.com
• Microsoft Store
• Bethesda Store
• Wikipedia and PCGamingWiki for reference information

Arx Libertatis (engine):

• arx-libertatis.org (official site and downloads)
• Mod DB
• GitHub
• Open Hub
• fresh(code)

Other Arx projects and community:

• Arx Insanity Mod, Arx Neuralis, AF UE4 Remastered, Arx – End Of Sun, and more Arx mods
• TTLG Forum, reddit, GOG.com Forum, Noden Gaming

Common points of confusion

"Is Arx Libertatis a free version of the game?" No. It is a free, open source engine, but the game data is not included and must be obtained separately.

"Can I play it without owning Arx Fatalis?" Only if you use the demo, which the project also supports as a data source. Otherwise you need a copy of the original game.

"Which platform should I pick?" If you are on Windows or Linux, you have official builds. On macOS, the Homebrew package is the documented route. On the BSDs, Haiku, or Pandora, use the packaged version for that system.