Dwarf Fortress (opens in new tab) came to Steam yesterday, but you probably already know that. In fact, there's a good chance you own it; Kitfox Games, which released a "premium" Steam version of DF, enlisted the help of economists (opens in new tab) before yesterday's release, and the ASCII version has been free for 16 years on the Bay 12 website (opens in new tab) After it was downloaded, they tried to predict how many units the game would eventually sell. The prediction was a bad one: about 160,000 units sold in two months.

Dwarf Fortress achieved that in less than 24 hours (open in new tab).

To be fair to Kitfox's poor economists, they described the experience of predicting DF sales numbers as "like trying to drive in the rearview mirror," with predictions ranging from less than 100,000 to over 1 million units in two months. This is not an indictment of their predictive abilities, but rather a testament to how difficult it is to accurately predict sales and the behavior of Steam's algorithm.

This is because while Kitfox had hits in their back catalog, they had never released a game with the vast history and enthusiastic fan base of Dwarf Fortress. It was always going to be a heretic.

In fact, as I write this, the most popular thread on the game's Steam discussion forum is a thread started by a bewildered user, asking if fans have been playing DF for free for 25 years and are just waiting for the opportunity to pay $30? (Opens in a new tab). I'm no economist, but in two months time, the higher of the earlier estimates may be much closer to the mark.

PCG is rather fond of the gaming world's best dwarf traumatizer, and in its review of Dwarf Fortress (opens in new tab), it gave the cleaned-up Steam version a high score of 84%, calling it "an experience like no other. It remains a super-complex failure simulator that "can't be half-baked," but let's be honest: what other free game has fans lining up long enough to plunk down $30 16 years after its release?