Before it became the megalith players know, love, and dedicate entire lifetimes to mastering, Dota was just a popular mod of other games like Warcraft 3. Perhaps, in a handful of years, we’ll be speaking similarly of Dota 2 mod Auto Chess—that is, if it really is as popular as it seems to be.
Source: Kotaku – Dota 2 Custom Mode Is Either One Of Steam’s Top Games Or A Glitch