Helbreath is a classic 2D fantasy MMORPG that dates back to the early 2000s. Its original client was written in C++ using DirectDraw and only ran on Windows. Erko Knoll, a developer from Estonia, has been rebuilding the client in Phaser 3 and React, and writing a brand new authoritative multiplayer server in C and .NET 10. The project is open source under the MIT license and is designed not as a finished game but as a base game template for anyone wanting to build a 2D RPG or MMORPG in the browser.
What Is the Helbreath Base Game?
The project is best described as a playable base client and server rather than a complete game. It already includes maps and world rendering, monsters and NPCs, player character customisation, grid-based movement, spells and visual effects, items and inventory, and a full combat system supporting melee, ranged and spell attacks in PvP, PvM and MvM settings.
The multiplayer server adds chat, buffs and debuffs, an authoritative server with client-side prediction and reconciliation, anti-hack timing guards, anti-combat-log disconnect grace, bump prevention, and multi-threaded world scheduling with single-threaded per-map simulation. Communication between client and server uses WebSockets with Protobuf messages.
A note on assets: the Helbreath game assets are proprietary and not in the public domain. Erko considers them abandonware, but recommends making your own legal assessment before using them for anything beyond hobby or community projects.
Tech Stack: Phaser 3, React, C and .NET 10
The client is built with TypeScript, Phaser 3, React and Radix UI. One of the architectural decisions worth noting is that the UI is rendered outside the game canvas as standard web UI, which makes it easier to build, scale and test independently from the game renderer.
The multiplayer server is built with C and .NET 10 using ASP.NET Core WebSockets for transport and Google Protobuf for the wire format. The project has been developed with significant AI assistance and is intentionally structured to be approachable for AI-assisted workflows and iterative expansion.
Who the Helbreath Base Game Is For
The project is aimed at Helbreath fans who want to explore or extend the game in a modern browser, hobby developers building 2D RPG or MMORPG-style projects who don't want to design the full stack from scratch, developers interested in Phaser with a React UI layer, and anyone wanting to experiment with or learn from an MMORPG server written in C#.
One project already built on top of it is Helbreath.xyz, a browser-based Helbreath MMORPG. Erko welcomes contributions, especially bug fixes, missing content, documentation and new original assets that stay aesthetically accurate to the original game.
Try the Demo and View the Source
There are two playable demos: a single-player client and a multiplayer client that connects to a hosted instance of the C server. The project is MIT licensed and contributions are welcome.