
Mapped mouse and keyboard to steam deck controls
Game runs perfectly. 90fps most of the time.
Some text is small, but still possible to read by default. I increased font size with https://github.com/Lyall/DAFix (configured scale at 0.9) and then there was no problem.
No native gamepad support, so you will need to be comfortable with editing your controller settings to map KB+M yourself. Almost everything can be done with just mouse anyway. My game automatically defaulted to "Khar's Dragon Age: Origins" community layout which I don't recommend because it maps right click to L5 instead of left trigger.
Plays nicely with proton-speedhack if you like being able to play in fast forward.

I have played about 40 hours on PC, playing on deck is extremely enjoyable when configured comfortably.
Spent some time getting controller comfortable, game runs near perfect.
set back grip to inventory, map, tactics, and pause

Built a radial menu on the left track pad for quick access to the menus.
Set TDP to 5, locked framerate to 60 Hz.

i just reconfugure save button on more comfortable position. Other buttons were mapped by community layout.
The text in in-game books and notes was difficult to read, so i gave up on deep lore experience. But I'm sure there is a mod which could fix this, I just didn't want to.
The game crushed only for 6 times, which was a decent experience for 2024 run (people on internet always strugle whith frequent crushes and are in need to instal extra mods to fix that, and nothing like that is needed on steam deck). The most crashes were during DLC awekekning, which is laggy AF anyway.
It was my first playthrough and I was expecting a lot of problems and crashing due to internet rewiews/reddit community/my friend's experience. But they were playing mostly on windows pc. It seems like linux experience is something else, especialy steam deck. It runs pretty well on max ultra grafic setting. Battery runs out fast (like I had 2,5 hours of gameplay on fully charged deck) which was a surprise for me, because I was expecting better performance. But I'm sure there are some optimal settings, which make batery life much more longlasting, I just didn't want to search for them.
The game starts out of the box. No other aditional settings are needed, you just pres play button and the game launches itself. Fortunately the game doesn't need additional EA launcher... For more comfortable gameplay I swiched to the community layout and the aditional change of resolution was needed to fit the screen properly. After that you are ready to explore the game world.
I was able to finish the game from start to the final credits, including the DLCs (note that the Awekening dlc is quite buggy) and the game crashed like maybe 6-7 times, so always have a quicksave button ready, just in case.
The main problem with the game is the bad control mapping. The game itself runs fine. Use the Community layout I suggested.
Go into the ... menu, Performance tab. Enable "Use per-game profile." Then set these values:
Framerate Limit: Unlimited
Refresh Rate: 30
Allow Tearing: On
TDP Limit: On
Watts: 5
Manual GPU Clock: On
GPU Clock Frequency: 600
Battery is close to 4 hours with these changes.
The game runs very well on the Steam Deck. It looks good and provides 4 hours of battery life with some simple tweaks to limit fps to 30 and lower the CPU/GPU power limits. The game mods very well too. More details on using Protontricks from the Discover store to install mods at https://gist.github.com/v1ld/bbff0fbfb89bf0255cb672b97e4f72c0

- I recommend utilizing action set layers. For example when I press L4 and then touch trackpad it will bring up F5/F9 radial menu that I can use to quick save or quick load.
- Also and this is a BIG ONE. Set your right stick outer zone to 1 and bind right-click to it. That way whenever you move the right stick, the right-click is automatically pressed and you can move the camera much like in normal games. This almost completely fixed controls for me. I use right trackpad as a mouse cursor.
- Set left stick not to WSAD but to WSQE.
- Set d-pad to map/inventory/journal etc.
TDP to 7
Install FtG UI mod to fix the fonts.
- download it from Nexus Mods
- add DAUpdater.exe (found in the DAO folder) as a non-steam game.
- set launch command of DAUpdater.exe to STEAM_COMPAT_DATA_PATH=the_compatdata_dir_for_dao%command% (change the_compatdata_dir_for_dao to compatdata folder path of DAO ultimate edition, folder should be named 47810 - but you need the full path)
- now install FTG UI mod with the DAUpdater
- In FTG UI folder find the .exe file that lets you configure the font sizes, add that as a non-steam game
- repeat step 3 for the confix .exe file (same path, just copy paste the launch command)
- Experiment with font sizes, I use something between 20 and 30.
This game requires a fair amount of tinkering to be enjoyable but I provided pretty much everything that you need to have a good time. Hope it helps someone!

Not recommended for a first playthrough because of a lack of controller support. DLCs did not work out of the box.
Installed physx
Game requires a lot of control customization to be comfortable on the Deck
I do not recommend playing a first playthrough on the Steam Deck, even though a very comfortable layout is possible with some tinkering.
Apart from the game not launching without physx installed, a lot of the DLCs simply do not work. I managed to enable the promo items and the DLC campaings seem to work, but apart from that i could not get the locations on the map to appear, including the extra companion.
made some graphics adjustments to improve battery life
This game has aknown controller mapping Via xbox360, there should be a way for us to get that controller layout. Sadly i am not linux savvy enough to know how to make that happen. The xbox controller layout would solve all of the input issues if it could be added as a patch.

Remapped basically everything to my own liking.
A - Space
B - J (Journal)
X - I (Inventory)
Y - C (Character)
Start button - Escape
Back button - M (map)
L1 - Scroll Down
R1 - Scroll Up
L2 - RMB
R2 - LMB
L5 - \ (mapped to Tactics)
R5 - ` (mapped to QuickSave as couldn't get F keys to work in game)
Left Stick Up - W
Left Stick Down - D
Left Stick Left - Q
Left Stick Right - E
Right Stick Left - A
Right Stick Right - D
D-Pad all set to normal arrow keys
Left Trackpad - Touch menu for 1-10 to pick hotbar icons
Right Trackpad - Mouse
Slowdown after some playtime, but googling shows this is common and not hardware specific. Simply save and restart the game to speed it up again.
Horrible bug in the Awakening DLC that causes main character to lose all items after a prison scene, but this is a community known bug and not a Deck issue.
Some texts are too small to read
There are some texture glitches, but I beileve it's due to the game poor memory management
It's pretty awkward to play it on steam deck
Some cutscenes were skipped
The launcher opens old Windows style settings, which are difficult to use on the Steam Deck (Analogstick, trackpoint and touchscreen). But you need to make the graphics settings there for 16:10 and "very high details". Is a bit fiddly
Problems with the mouse input. Trackpoint and gamepad buttons do not work for right click. Touchscreen is a bit difficult because of the size of the objects and no right click possible.
The game it self works fine , only the right-click on the mouse is missing and the launcher settings are a bit complicated. You need to use an external mouse to play properly.