

Will crash just after launching on non-standard resolutions (my screen is 2256x1504). Work around is to: set your system display to 1080p, launch the game, then while its running change your display back to what it should be. From there, fiddle with in-game display settings till it looks okay. Be sure to turn stretching off.

ive tried experimental, GE 9-23, 9.0-4, 8.0-5, and 7.0-6. same issue occurs.
upon opening the game through steam, it opens the ubisoft launcher, and you have to enter your password, and then the game loads the first few seconds of the ubisoft logo intro, and then freezes. you have to manually kill the program when this happens.
although my system info from steam lists the primary gpu as the integrated one, all of my games run on my discrete one, 3050 ti mobile

gamemoderun gamescope -w 1024 -h 576 -W 1920 -H 1080 -F fsr -f -r 60 -- %command%
The game runs with pretty low fps even though my PC could've have more on the lowest settings
Ubi connect makes me use my password every time I start the game. Also when I have to use the launcher itself it runs really slowly

mangohud %command%
Low textures quality
poor performance, stuttering.
Game crash at start
I can't play this game because he crash at the logos cutscenes, also have bad performance and graphical issues.

Runs good
The Ubisoft launcher is a minor annoyance.
- You have to re-enter your password every time.
- It needs to be killed manually after the exiting the games

Apart from some video and sound stuttering in the beginning of loading time, the game runs like a charm
Crackling in the beginning of the loading time
In the beginning of the loading time there's some video stuttering.
Apart from some video and sound stuttering in the beginning of loading process, you can enjoy playing this game.

Worked without any problems

DXVK_FRAME_RATE=60 AMD_VULKAN_ICD=RADV RADV_PERFTEST=gpl __GL_THREADED_OPTIMIZATIONS=1 %command%
If you fix possible launcher updating problems, you should be fine. You can manually download "Ubisoft Connect" and replace the installer in the game folder with the updated version.
Important though: Unity doesn't like "vertical sync" disabled in the graphics options. It leads to bad performance, control lag, physics bugs and random crashes. Always keep it on with this particular game, and you could add the following parameter to the launch options:
DXVK_FRAME_RATE=[your monitor refresh rate]
This is in case you disable VSync by mistake, which can crash your game at launch.

Used u/TiSoBr's method for bypassing the Ubisoft launcher password prompt, found here: https://old.reddit.com/r/SteamDeck/comments/vovl7c/just_a_quick_piece_of_advice_to_enjoy_ubisofts/ (remember to select "Remember Me" in the offline login prompt) - there was some weirdness in Ubisoft Connect trying to start the full launcher in offline mode, but exiting and trying the game again solved the issue.
Settings used:
- VSync - Off
- Stretching - Off
- Environment Quality - High
- Texture Quality - High
- Shadow Quality - High
- Ambient Occlusion - HBAO+
- Anti-Aliasing Quality - FXAA
- Bloom - On

The only crashes I've encountered were from taking screenshots.
Older Ubisoft games like this will require you to re-enter your Ubisoft account password every time you want to play. Just a minor annoyance, but it's worth mentioning.

40 fps TDP at 12 and GPU clock at 1300
Ubisoft Connect
Ubisoft Connect will have an error at initial login. This can be fixed by using a mobile device as a wifi Hotspot. For some reason, this will fix the error. This fix is only needed the first login. Afterwards you may need to sign in and different points but wifi works fine.

With the necessary changes made, the game runs smooth. Rare crashes are not a big problem due to frequent checkpoints.
Disable Steam Overlay or game crashes immediately after startup. After this, I had some rare crashes but overall could play just fine.

the game is pretty ok, no more UBI launcher problems nowdays on experimental, the graphics scale pretty nice, the game is cpu bound, so keep that in mind, a cap of 30 or 40 will do wonders and you can play for lots of hours with ajusted settings.

Tried Experimental, GE 8-2, 8-3, 8-13, 8-14, nothing. The earlier versions have a bug with Connect, the later freeze 2 seconds into launch.
PROTON_SET_GAME_DRIVE=1 WINEDLLOVERRIDES="version=n,b" %command%
I hate Ubisoft. Do keep in mind that while I was trying to use ACUFixes, not using it didn't fix anything.

ubisoft connect work, but crash just before the end of the first logo
tryied multiple version of proton, other "fixs", nothing work, same problem

I played around with wine and the local files because my game froze 2 seconds after starting. Here's what works for me:
- Switch Proton version to experimental.
- After the first start you have to verify the game files before every further start. It is normal that no bad files are found.
Notes:
- You have to re-enter your password every time you start the game.
- After closing the game, the game has to be closed again in steam due to the third party launcher.

before launching the game, follow the steps in this post https://www.protondb.com/app/289650#-4L_9452Q9, same as a pc setup
followed the steps in the below posts.
In order to get ubisoft connect working, youll need to boot into desktop mode after installing the game, follow the steps i posted above. Then open the konsole and use this command:
nmcli connection modify 'NetworkName' 802-11-wireless.mtu 1452
replace 'network name' with your wifi or ethernet name. (Note: Make sure to excersize caution when using this command (or any command really)).
Secondary note: If you havent set an admin password youll need to using command passwd before running this command.
After running this command, hit enter and youll open a new line. The konsole will give no indication that anything has happened but it will have went through. Restart your steam deck, start the game, and ubisoft connect should start and run normally. You will need to log in each time you want to play (unless you run the game in offline mode). However you will need to log in the first time (gotta love always online DRM, thanks Ubisoft).
Ubisoft LOVES making this process way more difficult then it needed to be. I'm sure if this was the epic games deck this wouldn't require so much tinkering.
slow loading textures
Only use proton 8.0.01. Other versions including experimental crash after the logo.
After the newest update game crashes after the ubi logo.
Game is now borked and will not launch properly.
Performance equal to windows, this game still looks beautiful, Nvidia exclusive features worked (not that many are worth it except HBAO+)
MANGOHUD=1 %command%
Renamed intro video files to speed up loading - .steam/steamapps/common/Assasin's Creed Unity/videos:
UbisoftLogo.bk2 pc_TWIMTBP.bk2
.steam/steamapps/common/Assasin's Creed Unity/videos/en: pc_WarningSaving.bk2 warning_disclaimer.bk2
I just added crap to the end of all of the filenames (before the .bk2 extension) which was handy for me to find them just then by searching for "crap" in the game folder.
Xbox One controller only worked when physically plugged in - with bluetooth only some of the axes moved properly - haven't investigated if this is common behaviour with all linux games.
Running at 4k Native - with FXAA, I don't use the Nvidia soft shadows or TXAA - if you use TXAA it will completely tank your performance, on any system. This game works as well as Windows out of the box with glorious eggroll.
Without glorious eggroll I was experiencing stutter quite frequently, so be sure to use glorious eggroll (Proton GE). Actually, I used Proton GE-8.2, I accidentally wrote 8.3. Haven't tried it with 8.3 but I assume it will work the same, if not better. Very enjoyable experience.
Obviously only use the mangohud command if you have mangohud installed and set it up either manually or with Goverlay (I recommend Goverlay, it's much easier to configure).
to get this game running properly, follow the steps in this post https://www.protondb.com/app/289650#-4L_9452Q9
the old version of uplay will say it is offline and refuse to launch the game. make sure to folow these steps BEFORE first running the game, otherwise youll need to reinstall and do these steps, it will not work if done after first run (probably because the old version gets installed and cant be replaced after).
Texture load in is brutally slow, this seems to be a problem on windows as well as this game is extremely buggy and unoptomized.
Overall a decent experience, once the uplay issue is fixed it plays about the same as on windows (i.e. buggy and poorly loading textures).

The game does not run, though it reaches the main menu. It does not run even at the lowest settings.
Game is borked for me.
Had to replace the out-dated UPlay with UbisoftConnect. Steps to reproduce:
- Vanilla installation of the game.
- BEFORE launching the game for the first time,
- Download Ubisoft Connect from Ubisoft's website: ubisoftconnect.com
- Find your game installation folder. Something akin to ~/.local/share/Steam/steamapps/common/Assassin's Creed Unity
- Under that folder, go to Support/Software/GameLauncher
- Remove the Uplay file you find here and replace it with the UbisoftConnectInstaller.exe that you downloaded.
- In the top-level game installation folder, find a file that end in
.vdf
. "find . -name *.vdf
" should return this filename. - Open that file in your editor of choice and find a line towards the end that looks like
"process 1" "%INSTALLDIR%\\Support\\Software\\GameLauncher\\UplayInstaller.exe"
and change "UplayInstaller.exe" such that it points at the UbisoftConnectInstaller.exe file you just placed. - Launch the game for the first time
- This should go through the usual DX11 steps as well as installing Ubisoft Connect. It may have you sign in to your Ubisoft Connect account, but it will add AC Unity to your Ubisoft library.
This should "just work" after that. There may be other settings you can add to improve stability or graphics, but this made running the game feel very vanilla. As if this is how it is meant to work. The one caveat is that exiting the game does not stop the game. You may have to stop it in Steam as well. This process was verified with AC Syndicate as well.
Everything is fine, but after a certain time Steam Deck freezes tightly! Only Hard reset helps! What is the problem?
The UPlay launcher which steam installs by default is outdated and logging in does not work, neither is the launcher able to update itself. I solved this by manually downloading the current launcher installer from ubisoft.com (a file called "UbisoftConnectInstaller.exe"). Run that installer using the proton experimental wine in the wineprefix for AC Unity. To do that, run in a terminal (assuming the downloaded installer is in ~/Downloads)
$ export WINEPREFIX=~/.local/share/Steam/steamapps/compatdata/289650/pfx $ ~/.local/share/Steam/steamapps/common/Proton\ -\ Experimental/files/bin/wine ~/Downloads/UbisoftConnectInstaller.exe
Once that is done, regular starting up from steam works fine and the game runs flawlessly.
- Set TDP Limit to 12W
- Set GPU Clock to 1300
- Set screen refresh to 60hz and FPS limit to 30
- Set to medium settings
Had originally set to 40z and 40FPS but kept dipping into the 30s.
The game worked pretty much flawlessly out of the box. I did make some performance tweaks to make it a bit more smooth.
The only other issue I had was with Ubisoft's Launcher. You need to sign in EVERY time you play. This can be remedied with offline mode, but wasn't too much of a bother for me.
Runs well out of the box. Recommend setting the FPS limit to 30 for a better & stable experience

Medium Preset Settings 40 FPS Lock 12 Wt TDP limit 1300 MGhz GPU Lock (help with stutters inside big crowd)
Crashes after displaying the nvidia icon. Tried to run on Proton 7.5, Proton GE 7.43, did not start and crashes after displaying nvidia
Was able to play the game once, but didn't start again after that
After changing some settings regarding fullscreen, resolution, the game doesn't want to start.
Despite resolution bugs and Ubisoft being pain in the ass, The overall exprience is great
DXVK_ASYNC=1 gamemoderun %command%
When game launches it's fullscreen but it's small section of screen that actually shows the game (top left of the screen) and other part of screen is blank, But you can fixing it by changing window type to Window and switch it back to Fullscreen.
You can't alt + tab if your are using tiling window manager with Fullscreen, and Borderless window is so buggy that even i can't explain it here, I found a fix for using Fullscreen and be able to alt + tab, first install protontricks and then execute this command:protontricks 289650 winecfg
then in the opened window go to Graphics and enable Emulate a virtual desktop then write your native resoltion and click ok, then execute this:protontricks 289650 mwo=enabled
now you may be able to alt + tab in Fullscreen but it also may create more bugs when using multimonitor setup.
Ubisoft cloud saving not works
30FPS capped from the Quick Access Menu.
Ubisoft manages cloud saving instead of Steam. Meaning if Ubisoft Connect fails to sync your save then it isn't cloud saved at all. You'll have to start the game again, perform anything that will cause a save and exit the game. Forcing the Ubisoft Connect launcher to close after a game has been closed also doesn't fix the issue and the Steam spinning logo never stops upon quitting the game. Aborting the game due to that issue is mandatary.
Cloud saving is done by the Ubisoft Connect launcher so it isn't as seamless as you would expect it to be.
Playing through the entire game, I have gotten stuck in a wall twice and my target has spawned under the level once. Reloading the last checkpoint fixes that.
Co-op works as intended and no issues accrued.
Played through the entire game from start to finish and it still shocks me that the Steam Deck can handle this game so well considering the amount of NPCs on screen.
Set graphics to medium. Set refresh rate to 40hz
Great game. But you need to log into UPlay to launch the game. Must be online on first launch.
Any further tries to launch the game are met with freezes, depending on your selected proton. Regular: ubisoft logo. experimental: main menu. GE produces the same results. only way i have managed to run the game again is by deleting proton files and going thru first time setup again. i have not tested any beta branches simply because i gave up.
uplay is kinda inconsistent but after that the game is flawless

I cannot fix this error `Failed to request product key from Steam, please try again in a few minutes`
Unity is borked if you have DLCs. This bug is due to the file appinfo.vdf which miscategorizes Ubisoft DLCs as being Mac games and tries to fetch a Mac key. I already have a Windows key for AC Unity. People in were able to get AC 2 to work by modifying appinfo.vdf, but no fix exists for AC Unity. Now I downloaded the Steam Metadata Editor which can read and modify appinfo.vdf, but it apparently can't modify DLC metadata, so it's kinda useless for my needs because the issue is that I need to recategorize the DLCs of AC Unity to be Windows and not Mac. I do not know how else to edit appinfo.vdf. If you know a way to edit DLCs on appinfo.vdf, let me know.

During Lockpicking, Spacebar wouldn't register
Slight Stutters sometimes, Very minor
FPS is lower than expected