
На официальных сборках proton ошибка 1-1002, требуется использовать Proton Experimental beta bleeding-edge - latest для нормальной работы.
В настройках Proton Experimental выбираем ветку "beta bleeding-edge - latest and untested dxvk, vkd3d-proton and wine changes", в настройках игры undecember выбираем версию Proton Experimental, запускам и ошибок нет, можно играть.

Anticheat nProtect shows an error and close the game.
The game installs, open, but in the menu screen the anti cheat nProtect show an alert and closes the game in sequence. Tried proton Experimental, 9xx, 7xx, no success.

nprotect Gamguard error 1-1002.Linux Mint 21.3 x86_64 , 5.15.0-113-generic , RTX 3060 , 64 GB RAM, nvidia-driver 535.183.01
Proton Experimental, 9.0-2, 8.0-5, 7.0-6, 6.3-8, 5.13-6, etc
Not working now. Oh well.

При запуске ошибка в главном меню 1-1002 с последующим вылетом игры, после обновления игры от 18.07.2024
До обновления игры от 18.07.2024 игралось всё нормально, если использовать не GE-Proton, а поставляемый в steam то некоторые видео файлы в игре выглядели как настроечная таблица, поэтому использовал именно GE-Proton. После обновления игры от 18.07.2024 ошибка в главном меню 1-1002 и просьба связаться с техподдержкой.

The game starts and runs without any problems. Tested on an endgame character. I highly recommend it!
Game isnt loading videos. For example, you can watch a short video of each skill. These videos don't work. This doesn't significantly affect gameplay but would be worth fixing.
The lack of videos for individual skills may be problematic for new players who have no idea how a given skill works. It doesn't affect the game significantly, but it's a bit of a dissatisfaction :)

The game work perfectly via Steam + default Proton. I run the game. Got all my characters. Every future at this moment is working for me.
Dont use Snap Steam version- Undecember isnt working on snap version. There is a problem with nprotect (anti-cheat)system. Regular steam version from official website work perfectly.

Undecember version 3.10.03 works. Lastest updates as of 09-29-23. All the changes (updates) over time made this game a lot better to play
Good graphics. Lots of options for character development: skills and gear. Some bosses used to be a little challenging on your first attempt. But, just keep skills, gear, and resistances updated and you should be fine. You can always kite a boss though..LOL.
Due to poor FPS performance even on low detail, even though playable, not optimal. My Graphic Drivers and hardware are outdated however.
PROTON_USE_WINED3D=1 %command% -windowed
Game would launch and could reach settings but upon pressing start button game would infinite load or crash while the fullscreen settings in game were on.
When the graphics were on high... FPS would get pretty low, but once I turned down the graphics its playable
When I first installed game game would not launch, changed launch options. Upon second launch of game proton installed C++ redistributable. Then game would launch. Sometimes game will have black screen. Relaunching fixed issue.
Game runs and is playable. I changed shader version to 3.1 and made the game windowed using in game settings. Got past title screen and loaded into game. Played Game. Crashed once. Infinite Load Once. Black screen once. Other than that give it a try and tell us how it runs on your system.

Game opens but freezes in a loading screen after clicking to enter a server
First screen in the game shows SMPTE color bars but I can interact with the menu. When clicking to actually enter the game it freezes in a loading screen with a game image and ambient sound.
Good graphics, gameplay is good. Will play more. I was asked to install C++ redistributable files when I launced the game. It worked.
Proton 7.0-5

Minor texture weirdness that doesn't affect gameplay.
Game occasionally doesn't load, but does work after force closing and restarting it.
Game will not progress past initial setup screen with Proton 7.0-5. Works after switching to GE-Proton.
new update make disaster
The first time I played this game there was no problem, but with the new update I got a black screen and got stuck when nProtect gameguard appeared and didn't run the anti-cheat
NProtect closes the game with a illegal use detected error message.
Borked
After game start a error message with illegal use detected pops up and a NProtect error window opens.
Game does not start.
Just worked out of the Box, no Tinkering nothing. Works flowlessly!
its a nice alternative to Diablo & POE

it works.
For about the first hour of play I experienced stuttering every once in a while it appared to be something to do with shader caching.
its fine.
Runs good out of the box.
After 4.5 hours of gameplay I can say it runs good without any problems.
Runs OOTB
nProtect seems to play along nicely with Proton
gamemoderun %command%
Would not connect to server with default Steam Proton
Runs great. Input is a little wonky for some menus, but mostly due to game being a ported mobile game, not proton.
If wine prompts to install extra dlls/libraries, just walk through that menu until it finishes installing them.
Created a Radial Menu for menu hotkeys
Set game to fullscreen 1152x864 and enabled FSR. Capped FPS to 40 and TDP to 11 watts.
This game works well, but will require a little tweaking on Steam Deck to get the best ratio of performance vs battery life. Default settings at 60 FPS yields around 1 hour 20 minutes of battery. However this requires you to go into the game's settings and switch graphics from Quality to Performance. This results in a very noticeable hit to both graphical fidelity and resolution. It looks much better if you leave it on Quality and set the resolution to 1152x864 and then enable FSR on the Deck. If you additionally cap FPS at 40 and limit TDP to 11 watts, you'll get around 2.5 hours of battery. With these settings the game runs very smoothly and works very well.

Back Grips for Inventory, Skills etc
Small as expected but everything was readable
I played into Chapter 2, great experience on Deck. Action-driven isometric Online-RPG, recommended.

Anti-cheat closes down the game. Tested Proton Experimental and GE-Proton-7-37
Borked

Demo runs well, has touch/mouse interface that was troublesome to click on some of the small icons. Small hud. Game hung on lauch with default proton.
Demo doesn't work, stuck on white screen
Tried both Proton 7.0-4 and Proton Experimental
Proton 7.0-4 launches past splash screen to a white screen, with the game's cursor. Proton Experimental just gets to the white screen, no cursor.
The game uses "nProtect GameGuard" anti-cheat rootkit (!!), although it's not clear if the anti-cheat is active for the demo.
AntiCheat windows shows and ends the process

(Demo Version) Works surprinsignly well, the anticheat seems to work on Linux, at least on the demo version (or maybe it's just disabled)
Needs touchscreen on login screen (controller and trackpad are unresponsive), but then it works fine
Didn't tried to play with someone else, but i played until the first city, and i found other players around as expected
Needs touchscreen on login screen (controller and trackpad are unresponsive), but then it works fine. Controllers are supported, even if the interface isn't really desinged for them. you can switch from "action" to "cursor" mode pressing the start button. But i found touchscreen more comfortable. Performance are acceptable for the deck (30-40 fps at max settings) The game has an anticheat, it's possible to view it's loading screen at startup. But it seems like to work along well with Linux, at least on the demo.