When the company launched the original Source Engine back in 2004 it did so with a beta for a new version of Counter-Strike (Counter-Strike: Source) and then went wide a few months later with Half-life 2. The first game running on Valve's follow-up engine, Source 2? Dota 2.
Specifically, Dota 2 Reborn. As Eurogamer points out, the multiplayer online battle arena (MOBA) has been running in Source 2 in beta since June, but now the game's sporting a new UI and more game modes on Source 2, including support for 20-person matches.
Valve is responding to its player-base here. In 2004, Counter Strike was the competitive game to play. But while Counter-Strike: Global Offensive is still really big on the scene, MOBAs are where the action's at for eSports.
