Steam Deck FAQ: Accounts, microSD Cards, and Non-Steam Games

Thinking about buying a Steam Deck, or sharing one with family? A few simple questions come up again and again. Valve’s Steam Deck FAQ answers several of them, so here are the ones about accounts, memory cards, and games from outside Steam.

One note first. Valve’s FAQ page carries a 2022 copyright line, so it reflects the early days of the handheld. If a menu looks different on your Deck, trust what you see on screen.

Can you have more than one Steam account on a Steam Deck?

Yes. Valve says each account on a Steam Deck keeps its own local save data and settings.

In plain words, you and a sibling can use the same handheld without messing up each other’s progress. Your settings stay yours. Their saves stay theirs.

What format does a microSD card use?

Valve says microSD cards on Steam Deck use ext4 with casefolding. A file system is the way a card organizes its files, and this one is common on Linux devices. Valve also says the Steam Deck formats SD cards to the proper format for you.

That means you don’t need to pick the format yourself. A card made for Windows or another device may not work as-is, so expect the Deck to prepare it.

Back up anything on a card before you put it in. Formatting is how a card gets ready to use, and it changes how the card is organized.

Can you boot another operating system from the card?

Yes. Valve’s FAQ says Steam Deck supports boot from microSD. Another answer says users can reach the BIOS menu and that multi-boot is supported.

Booting means starting the device from the operating system stored on a card instead of the built-in drive. It’s a tool for people who like to tinker. Most players can skip it.

Can you run games that aren’t from Steam?

Yes. Valve says you can run non-Steam games through Proton. Proton is Valve’s tool that lets Windows games run on the Deck’s Linux-based system.

Valve also says improvements to Proton, such as anti-cheat support, will reach all systems that use Proton. Another FAQ answer says Valve would support adding games like it does in the desktop Steam client. Valve wrote that line in future tense, so check your own Deck to see how it works today.

What does the FAQ not tell you?

Valve’s FAQ does not list supported card brands or sizes. It also does not give menu steps for formatting a card, installing games to it, or moving games between drives. For those, look at the storage settings on your own Steam Deck.

Already own a Deck? Try this: open the settings, look at your storage, and see which drive holds your biggest game.