Most companies will launch their new game engines with a quick little sizzle reel or tech demo showing off how spectacular their new engine looks and fill in devs on the back-end bells and whistles later. Valve isn’t most companies, though. While we knew they were working on Source 2 behind the scenes, the first look at Source 2 in the wild appears to be in the Steam Workshop Tools for Dota 2.

Inquiring Dota 2 workshop creators and interested Valve fans made the apparent discovery when reverse engineering the Workshop Tools release for Dota 2. In the source code are references to Source 2, various files named with the number 2 on the end and the Hammer map editor allowing creators to save files as “Valve Map Files” or “Source 1.0 Map Files.” The implication of all this is that the update is in the Source 2 game engine.

At the moment, Source 2 requires a 64-bit Windows operating system and a DirectX 11 compatible graphics card. Anecdotal evidence suggests the switch from 32-bit to 64-bit makes Dota 2 load faster than in Source 1. It apparently also adds improved lighting and particle effects. One interesting observation many have made is that Source 2 appears to be backwards compatible with Source 1 assets. If that’s true, many devs working in Source and still a ways from release could make that switch without really losing any time or money. I’d imagine everyone at Respawn working on Titanfall 2 just got really excited that they don’t have to start from scratch on the sequel… unless they don’t develop the game for Source 2.

The existence of Source 2 was never really in question. Valve confirmed they were working on the engine as far back as 2012. We also saw evidence of work on Left4Dead 3 in Source 2 back in August 2013 during a tour of Valve HQ by teams in Seattle for The International 2013. That would have been an expected reveal of Source 2. This does keep us guessing a little bit longer.

Sources: Extreme Tech, Eurogamer, GameSpot