There have been few indie gaming success stories as big as Dwarf Fortress, an ASCII freeware simulation game in which the player helps to establish and govern a colony of dwarves, as they construct a Moria of their own.

The scope of the game defies belief: it contains an extensive world generator, a three-dimensional cellular automata system for simulating fluids, naming languages for all major races, an economics simulation, and even a complete Adventure Mode in which the player can explore abandoned fortresses.

It's so detailed that large web communities have sprung up around the game, both on the developer's forums and Something Awful, where players trade stories about what happened in their games. Some of these stories have even become popular outside the game's community.

Amazingly for a game as rich as Dwarf Fortress, it remains the work of just te wo people, programmer Tarn "Toady One" Adams and his brother Zach. Tarn supports himself primarily with donations from Dwarf Fortress enthusiasts. In this interview, Tarn talks about the inspiration and origins of the game, and some of the finer points of its construction.

This interview was originally held over a private IRC conversation, and edited into a more traditional interview format.

Games Leading Up To Dwarf Fortress

Why don't we start with what gave you the inspiration to create Dwarf Fortress?

Tarn Adams: It's really the joining of two different tracks of development. The first has to do with our (my brother Zach Adams and I) "fantasy game." Way back when, like, when I was in elementary school, fifth grade or so, I wrote a BASIC game called dragslay. That was just a D&D game, more or less, with text that scrolled up from the bottom of the screen.

You mean Infocom-style?

TA: Pretty much, yeah. But it didn't even have a map. Just a line through 8 or 10 encounters, then a dragon fight, then repeat. It was very basic, but it was our first project. Our first fantasy project, rather. We had a ton of other space/samurai/etc. things going on, all BASIC, all very small, so we didn't do so much with it. Then in the summer of my freshman year in high school, I picked up C and dragslay was revisited.

So I was able to make a larger project. Dragslay was sort of horrifying. You could kill an enemy and then be attacked by maggots from the corpse at random. Wounds could fester as well then you'd catch diseases.

In any case, yeah, this time it got a basic world map, and you could depopulate goblin tribes in the wilderness as you searched for dragons. Along with several other projects, we worked on that until, say, my sophomore year of college.

So the game kept track of goblin populations?

TA: Yeah, it was one of my first save/load experiences outside of score lists. It kept track of their names and kills and they could yell at you like the enemies do in Dwarf Fortress. It was really quite far along, farther along than DF adventure mode in some respects. By yell at you, I mean it would track which players they had killed then they'd proceed to make fun of you. They also stacked their skulls outside the caves.