While Steam doesn´t have official controllers (the Steam Controller notwithstanding), it has supported alternative gamepads and control schemes for a long time. Any gamepad with an internal gyro that you connect via Steam will still retain its motion controls capabilities.
And while it´s true that you can also connect pretty much every gamepad out there to the Deck, does the machine itself have motion controls? Or are you forced to use a gamepad to enjoy them?
Does the Steam deck have a gyro?
Yes, the Steam Deck does have a built-in gyro. It is capable of using the said gyro to enable motion controls.
Gyroscopes are devices that, along with a couple of other sensors, can measure the speed and direction in which they move.
This information is sent to the game, the speed and direction in which you moved the Deck are translated into motion controls. The system is remarkably similar to the one the Nintendo Switch has, at it works pretty much the same. Time will tell if the Deck´s gyro ends up more or less accurate than the one the Switch has.
You might find it annoying that the cursor will move every time you sway your Deck left and right, but you have the option to turn on stick enabled gyro, meaning that your motions will only register when you click the stick or the trackpad, and not before.
Now, it´s important to remember that just because the Deck can use motion controls, doesn´t mean that all the games will support them. Just like it happens with the games on Steam, and how it happens on the Switch with a limited selection of motion control games, not all titles are guaranteed to be compatible with the feature.
Is the Steam Deck compatible with controllers that have a gyro?
Yes, the Steam Deck is not so much a console, but a portable computer with Valve´s custom Os that lets it be compatible with pretty much all the games for Windows.
Even if you find the Deck´s gyro to be clunky, or are using the dock to play on your TV, you have an additional option to enjoy motion controls. Connect to it a gamepad with a gyro, like the Dualshock or the Pro Controller, and you can enjoy them with all their features.
All the controllers that were compatible with Steam, should work with the Deck as if they were connected to Steam on a regular Windows computer. This means that all the extra features they might have; rumble, turbo, and yes, even motion controls, should all work so long as they did on regular Steam.
But are motion controls worth it? While they do have a bit of a reputation, thanks in large part due to the shovelware on the Wii, you will find that nowadays they are an excellent aid in helping you fine-tune your aim. If you haven´t, give them a try on your Steam Deck.
By the same token, is the Deck compatible with VR headsets? The answer is yes, but only technically. You still can´t play with them without using a dock.