Why is the next Half-Life game VR only?

Valve’s announcement of a Half-Life game for virtual reality carries with it the obvious question: Why? And why VR only?

Geoff Keighley put the question to three Valve developers in a 20-minute interview released today, even noting suspicion that Valve is leveraging a popular name to move its pricey Valve Index headset, which launched this summer.

The answer, according to Valve developer Dario Casali, is that the action inside Half-Life: Alyx is too detailed to map over to a keyboard-and-mouse game. Indeed, Keighley references a reloading process that involves reaching for a clip and slapping it into the weapon, although he called it intuitively done.

“The more we used the controllers and the headset, the more we realized the amount of interactions, the possibilities these things give us, the more we explored it, the more we realized that there’s so much opportunity that we can’t really translate back to the keyboard,” Casali said. “When you can track your hands separate from your head, all 3D space, all simultaneously tracking and moving, you can’t really get that with a mouse and keyboard.”

And to be clear, this Half-Life project originated as “an exploration of VR,” Casali noted. Valve’s Robin Walker explained, partially, why Half-Life: Alyx was conceived as a VR project at first.

“Back in 2016 when we started this, Half-Life 3 was a terrifyingly daunting prospect,” Walker admitted. “To some extent, VR was a way we could fool ourselves into believing we had a way to do this. By starting with VR and trying to think about Half-Life and how it worked with it, and play-testing those things, you’re immediately in a space where we have something we understand well — Half-Life’s core gameplay — and a new platform with new prospects with new possibilities, and we can do that translation, and we can watch people play it.

“It was easy to not think about the big picture — ‘We’re making Half-Life 3!’ — and just focus on what people enjoy and make forward progress,” Walker added.

Casali said that in order to bring Half-Life: Alyx to the PC as a flat-screen game, “we would have to map an entire section of the keyboard, dedicated just to interacting with doors.” He went on describe action in which a player may partially open a door, peek through it, shut it before it fully opens, or stick a weapon through the crack and fire it, or even drop a grenade and slam the door shut. All of that is carried out in an intuitive way in virtual reality, Casali noted.

“You end up watering down the VR experience, to do both at the same time,” added David Speyrer. “And the process was really, ‘What can we do with these controllers and the HMD?’ As we explored that idea, it just drove us into a place where the idea became essentially VR, rather than just kind of superficially VR.”

Half-Life: Alyx is slated for a March 2020 release on Steam. It is compatible with all PC-based VR headsets, not just Valve Index but also the Oculus Rift, HTC Vive, and Windows Mixed Reality. However, Half-Life: Alyx is free for owners of the $999 Index, and $59.99 for others.