DayZ Creator Dean Hall Backs Brutal Open-Source Game Framework

Dean Hall, creator of DayZ, has put a sharp name to a long-running concern for game developers: the tools used to make a game can become a dependency as consequential as any publishing deal. His answer is Brutal, a free, open-source C# framework from RocketWerkz intended to give technically equipped teams a starting point for building their own game-specific technology rather than committing entirely to a major commercial engine.

Hall’s argument is not that every developer should abandon Unity, Unreal Engine, or other established options tomorrow. He explicitly says Brutal is not a universal-purpose solution. The proposition is narrower, and potentially more important: a studio with unusual technical needs may be better served by controlling its foundations than by spending years adapting its game around an all-purpose engine’s priorities, pricing, and limitations.

That debate has a concrete test case already. RocketWerkz’s forthcoming Kitten Space Agency uses Brutal directly, while Ludeon Studios has rebuilt RimWorld around its own Waylith Engine using Brutal as a foundation. Ludeon says the game should look and play the same, but that its internal tests show performance improvements of between two and four times. A Waylith-powered version is available through a Steam beta branch, and the studio says mods are not expected to break.

Brutal is a framework, not a ready-made engine

The distinction is central to understanding what RocketWerkz has released. A game engine is commonly the broad collection of systems used to make and run a game: rendering, audio, input, physics, asset handling, user-interface tools, build processes, debugging support, and more. Off-the-shelf engines offer many of these systems together, along with workflows intended to get projects moving quickly.

Brutal is instead described as a C# framework. C#, pronounced “C sharp,” is a programming language widely used in game development. A framework supplies reusable structures and code on which developers can build. That can make it a powerful base for a purpose-built engine, but it also puts more responsibility on the studio adopting it. Teams must decide what tools and systems their own project needs, then build, integrate, or maintain them.

That is why Hall is not portraying Brutal as a comfortable replacement for every smaller team or first-time developer. Felipe Falanghe, creator of Kerbal Space Program, compared working with it to choosing a bar stool while users of engines such as Godot sit on comfortable couches. The image is useful: a framework may be leaner and more direct for a particular job, but it does not promise every convenience expected from a mature, full-featured engine.

Hall has separately made clear that his criticism is not directed at Godot, which he regards as strong technology. His focus is on the concentration of influence around major engine providers, especially Unity and Unreal Engine, and on what happens when developers have invested so much time in a toolchain that switching becomes financially or technically punishing.

RimWorld offers a real-world proof point, with caveats

RimWorld matters here because it is not a hypothetical project or a tech demonstration. It is an established game with a specific set of performance demands and a modding community that needs consideration during any deep technical transition. Hall says Ludeon extracted the remaining Unity components from the game to create Waylith, demonstrating the type of outcome Brutal is meant to enable.

The practical appeal is straightforward. Instead of creating every low-level foundation from scratch, a studio can begin with a framework and shape an engine around its own game. That could mean prioritizing the systems that matter most to its project and avoiding work on features it does not need. In Ludeon’s case, the reported performance gains are notable, but they should still be understood as the studio’s own test result rather than a guarantee that another game will receive the same benefit.

A tailored engine is not automatically better. It can require specialist engineers, long-term maintenance, internal documentation, and a willingness to own problems that a commercial engine vendor might otherwise solve. A bespoke approach can also create its own risks if the people who understand the technology leave a studio. Brutal’s case is not that such costs disappear; it is that, for the right team, those costs may be preferable to the constraints of a general platform.

Ludeon has also said Waylith will support more than RimWorld. The studio is working on a new project using the engine, though it has not shared details. That makes the migration more than an optimization exercise. It suggests that an in-house technology stack may become a reusable part of the studio’s future work.

The business concern behind the technology

Hall’s criticism is ultimately about leverage. He argues that developers are only as independent as the tools they rely on, particularly when a game’s production, released build, updates, and community support are all bound to a vendor’s ecosystem. Changing engines late in development can be enormously difficult; rebuilding a shipped title’s technological base is difficult too. The cost of moving can leave teams feeling as though they have little room to negotiate.

The 2023 controversy over Unity’s proposed install fees remains a major reference point in that conversation. The policy was met with widespread criticism and was later reversed, but it illustrated why licensing changes can feel especially alarming to studios that have already committed years of work to a platform. A game engine is not just software purchased at the beginning of a project; it can become woven into every pipeline, tool, asset, and release plan.

Hall is concerned that the rise of AI-assisted and agent-led development, reverse engineering, and recompilation could further reshape the competitive advantages that protected established software companies. Those terms cover different activities. Agentic workflows broadly refer to AI systems that can carry out multi-step tasks with some autonomy. Reverse engineering means examining software or systems to understand how they work. Recompilation is the process of turning code into a new executable program build. Hall’s view is that changes in these areas may weaken traditional advantages held by software platforms, potentially increasing pressure on providers to seek revenue through royalties, subscriptions, or tighter licenses.

That is an analysis and a warning, not an established outcome. But it explains why Brutal’s licensing model is as important as its technical ambitions. RocketWerkz says Brutal can be used at no cost, including in commercial games, with no royalty or percentage of a game’s revenue owed. Users are required to retain the copyright notice in credits and project files and display the Brutal logo at startup. Hall says a separate commercial licence can be arranged for developers who do not want to meet those attribution requirements.

Open source means an exit route, not an absence of work

“Open source” means the source code is publicly available for inspection and use under the project’s licence terms. In practice, the key concept in Hall’s pitch is the ability to fork the framework. A fork is an independent copy of a software project that a developer or organization can continue changing on its own path.

For Hall, that option is a safeguard. If RocketWerkz eventually fails to serve developers well, studios using Brutal should be able to take the framework and continue independently rather than being locked into a provider’s decisions. It is a deliberately different relationship from one where the core technology, road map, and terms are controlled by a single commercial owner.

That freedom does not mean a team can ignore the difficult parts. Having code available does not create engineering capacity, establish technical standards, solve compatibility issues, or keep a project’s tooling healthy. It does, however, mean that a studio is not structurally prevented from doing that work itself or collaborating with others to do it.

The broader issue is not unique to engines. Studios constantly make decisions about third-party middleware, storefronts, online services, platform holders, and other services that become embedded in production. As a separate example of how platform and ecosystem costs can shape technology choices, hardware pricing can also alter the economics of a connected ecosystem. Brutal is aimed at the development side of that larger question: what choices remain once an organization has built its work around somebody else’s infrastructure?

A collaboration, not a one-person manifesto

Hall has emphasized that Brutal is the result of work by many people at RocketWerkz, plus outside collaborators. He says people with experience at some of the world’s largest game companies have joined the effort. Falanghe has also said he used Brutal for his next project after leaving Kerbal Space Program without rights to that series, and that the new game is close to being ready to show.

Those names give the framework credibility, but they do not settle the wider engine argument. Unreal, Unity, Godot, proprietary engines, and smaller frameworks solve different problems for different teams. A studio prioritizing extensive built-in tooling may reasonably choose a conventional engine. A studio with a mature engineering group, a defined technical target, and concerns about future licence exposure may see more value in owning its layer of the stack.

Brutal’s most meaningful contribution may be to make that second option less daunting. It does not eliminate the engineering burden of custom technology, and it is not being sold as a magic escape hatch. But RimWorld and Waylith provide a visible indication that an established game can transition away from Unity while keeping its identity and mod ecosystem in view. For developers wary of the power held by engine vendors, that is more persuasive than a manifesto alone.

Hall’s language about the industry is deliberately severe, and his criticisms of Unity, Unreal, and Epic are his own. The durable point beneath the rhetoric is more measured: tool choice is also a question of governance. Brutal is an attempt to give developers who have the capacity to build lower in the stack a public foundation, a royalty-free route for commercial work, and the option to leave even its own creators behind if they ever need to.