Erynar: As I understand it, Google Stadia is Linux-based, and for better or worse BG3 is going to be on Stadia, so that strongly implies that most of the work necessary to release a Linux version on Steam and GoG will have been done
kodos_der_henker: Android is also Linux based and we see games having an Android version additional to Windows and Mac but not for Linux. So I don't think that being ready for Stadia indicates that native Linux will come
Fair point, though the Android situation is rather different. For Android, it's just the kernel that's Linux, and then they built their own stuff on top of it, with apps normally being written in Java. For Stadia, the main target will be native applications, and Google has stated that they're going to be running x86 processors with Linux, using the Vulkan API as their graphics API (wikipedia mentions both in their page on Stadia). That means that anyone writing a game to run on Stadia is going to be targeting x86 (clearly x86-64) using Vulkan, which is the biggest hurdle for anyone wanting to make their game run on normal Linux.
It's certainly possible that Google has mucked with the system API and some other aspects of the environment so that there are Stadia-specific things which wouldn't be compatible with having it run on desktop Linux, and there are going to be other details that need to be dealt with to make it run as a desktop application on Linux. So, it's not like the fact that something runs on Stadia guarantees that it will run on Linux without extra work or that the company making the game will release it on Linux, but the biggest technical hurdles are solved. It's going to be written to work on the right architecture with a graphics API that's compatible with Linux with it running on some version of Linux, albeit with it being server Linux, not desktop Linux. It's not going to be written to use something like DirectX, and it's not going to be written assuming Windows, which tend to be the biggest technical reasons why Windows games don't get ported to Linux.
Now, will Larian actually release a Linux version? I have no idea, but from what I understand, their code at least will be mostly compatible with desktop Linux, meaning that the odds should be much higher that they would be otherwise - especially if they have for other games in the past.
waltc: Actually, Stadia officially supports Windows, OS X, iOS, and Android--at least that is what Google officially stated yesterday.
https://www.guru3d.com/news-story/google-stadia-cloud-game-service-to-launch-in-november-for-10-per-month.html Look under
Supported Operating Systems. Linux is not mentioned. Stadia is purely a streaming service, though, so perhaps what may be supported is the Chrome browser for Linux--if such exists. But so far there is no info to that effect. BG3, btw, is being generally released by Larian--it's not just for Stadia.
That's for the client end - so the stuff that can receive the streams, not what's actually running the game, since it's running on the server. The real question is how much work the developers have to go to to make it work on desktop Linux, and Stadia is going to be running on Linux servers regardless of what the client is running. That's not the same as running it on a Linux desktop (especially since odds are that Google isn't simply running the server version of a Linux distro), but it means that the biggest technical hurdles to getting it running on the Linux desktop will already have been solved.
Of course, even if they were literally running the equivalent of binaries for SteamOS on Stadia, Larian would still have to decide that they wanted to release the game for desktop Linux on Steam and/or GoG, and that's not a technical decision. It's a business decision. So, even if we knew for a fact that it was trivial for Larian to get BG3 working on the Linux desktop after getting it working on Stadia, that wouldn't tell us that they'd do it - just that the problem wouldn't be technical. So, we'll just have to wait and see what they do.