Half-Life 3 reportedly isn't in development, but a new Half-Life game for the Steam Deck is.
The new report comes from Valve News Network creator Tyler McVicker, as reported by PCGamesN. According to McVicker, Half-Life 3 isn't in active development, and in fact, no traditional mouse and keyboard FPS games are in active development whatsoever at Valve right now.
What is in development, according to McVicker, is a RTS/FPS co-op game set in the Half-Life universe. This project is described as a "nostalgia-fest" by McVicker, incorporating elements of Left4Dead, Alien Swarm, and RTS games for something that'll show off what the forthcoming Steam Deck is capable of.
Through the new PCGamesN report, McVicker reveals that he's obtained the majority of his information through datamines of regularly-updated Valve software, and has been researching this project, which is codenamed "Citadel," since early 2018. The original report speculates that we should see Citadel within the next two to two-and-a-half years.
While we'll be waiting a while to see what comes of this mysterious new project, we won't be waiting so long for the Steam Deck. Although Valve just delayed the new handheld device out of launching later this year in December, it's now slated to launch in February 2022. We've already seen the likes of The Witcher 3 running on the device (and it looks really, really good), and we've even gone hands-on with Valve's new device for ourselves, which you can read all about in our full Steam Deck preview.
You can also check out our Steam Deck comparisons guide to see how it stacks up against new-gen consoles.