Inside Dwarf Fortress: 20 Years, 700k Lines, and Endless Development

Dwarf Fortress, first released in 2006, is hailed as one of the most epic computer programs for its pioneering rule‑based world generation that inspired games like Minecraft.

The game has been developed almost entirely by a single programmer, Tarn "Toady One" Adams, who left his university math professorship in 2002 to work full‑time on the project and has never stopped, resulting in a codebase that now exceeds 700,000 lines.

Adams writes the game in C and C++ using Microsoft Visual Studio (now the Community edition), OpenGL, and SDL, relying almost exclusively on built‑in libraries and only occasional random‑number generators such as Mersenne Twister and SplitMix64.

Dwarf Fortress offers three interlinked modes: fortress building, a roguelike adventure mode, and a legends mode that records the world’s history, all rendered with ASCII graphics that give the game its distinctive, surreal visual style.

Throughout its 20‑year history the project has seen virtually no large‑scale refactoring; instead, Adams makes incremental changes, uses descriptive naming, long variable names, and extensive comments to keep the code understandable years later.

Funding has come from player donations, allowing Adams to live on a modest budget (about $860 rent per month) and to refuse commercial offers, keeping the game free for over a decade.

In 2019, facing personal medical expenses, Adams launched a paid Steam version, which provided the necessary financial cushion while preserving the game’s core philosophy.

Future development focuses on a UI‑enhanced Steam version and the addition of AI‑controlled antagonists that will act as new villains across the game’s modes.

The project’s longevity and unconventional development approach have earned it a place in the New York Museum of Modern Art and have profoundly influenced other developers, most notably the creator of Minecraft.

“Develop until death, never stop updating.”