The purpose of this guide is to gather info in 1 place that I had to get from Googling and Reddit threads, plus my own experience, to help others.

First off, this is for those who have a regular PC account, with chapters, crowns ect. bought through the elderscrollsonline.com Store. You can buy the standard addition (Base game plus Morrowind) on Steam, which as of posting this is on sale in the Steam Store for $5.99. After installing the game it will ask if you have an existing account. Say yes and it will provide you with a code which you can then enter here: https://account.elderscrollsonline.com/en-us/link

Once your account is linked you will have access to to all DLC you had access to before without buying anything else. You also won't have to install anything new, though I will note the install size is over 100 Gbs, (128.27 GB) so make sure you have space. You also will not need to enter a password each time you launch the game, so you may want to make sure you have one for your Steam Deck. It will preserve your settings too, so things like "Prevent attack innocents" was on all my characters except the Dark Brotherhood one.

Once you start the game up for the first time, say yes to accessibility mode! This will put you in gamepad mode, which will activate the deck's controls. If you say no you will be limited to the touch screen, which is not the end of the world but still a big pain. For instance, when selecting NA/EU server, you must tap the exact dot to highlight and tap it again to select. I needed to repeatedly double tap the screen till I got it. Tapping the [E] to continue is much easier, though you can also press Steam button + X to bring up the keyboard. (Steam button + shoulder button to zoom will not help make it easier to tap.) Tapping the bar will scroll the EULA so you can agree to it. (Note: keyboard will not work to skip cinematic, just double tap screen.)

Once you are on the character screen, tap Settings > Accessibility and double tap the Off to switch it On. (This becomes easier with practice.) Each time you start the game up it may bring you to this menu. Press B to close menu and continue. If you press A, it will change the highlighted option, which in this case will turn On to Off.

If you have never used game pad mode, it will take some getting use to. By default:
A = Jump/confirm/interact
B = cancel
X, Y, B, Left shoulder, Right should are your skills (your hot bar will also show which skill to which button)
Left + Right shoulder = Ult
Left trigger = block
Right trigger = attack
Left stick to move
Right stick to move camera, press to crouch
Up D-pad = quick slot use, hold and use right stick to cycle
Down D-pad = first person toggle, hold and use right stick to adjust camera distance
Left D-pad = weapon swap
Right D-pad = cycle quests
Windowed Key (above D-pad) = Map, press to call mount
Menu key (above X) = game menu
Things are organized a little different, for instance, Social will contain your guilds and you mail.

I bound press Left stick for dodge roll. Works great, I can press and tilt forward to forward dodge. In the menu press A for Options>Controls>General>Movement. Left stick/D-Pad to move to a 'Not Bound' slot. Press A to select, A again to ready for input. press the desired key, it will look like a side view of the stick with a down arrow above. Press X to confirm.

You can also apparently use add-ons, someone more familiar with this, can you comment below.


Question: Why do this?

Well for starters, if you play on a PC and happen to have a Steam Deck, it can be a backup option if you have a 256 GB size or larger. If you buy the base game for cheap on sale, it will be in your library, you can install it as needed should your PC break.

It's also a good option for travel. I've been lugging a cheap gaming laptop with me on my trips, not one to judge. These are questions I had, I hope the info here can help someone else.