It depends entirely on the device type:
No key needed. These are self-contained units with games baked into firmware.
Just connect power + HDMI/RCA, turn on, and play.
No key needed. Insert the physical game cartridge → play. The cartridge is the license.
Yes, for digital games. You need a product key / download code (12–25 alphanumeric chars) to redeem on the console's store. Physical discs don't need a key—the disc authenticates.
Yes, for most digital titles. Keys activate the license on the platform. Some DRM-free stores (GOG, itch.io) just use account login.
| Device Type | Game Key Required? |
|---|---|
| Dedicated Plug-and-Play (Classic Mini, Flashback) | No |
| Cartridge Console (NES, SNES, Genesis, N64...) | No |
| Modern Console Digital Game | Yes |
| Modern Console Physical Disc | No (disc = license) |
| PC Digital Game | Yes (usually) |
If you have a specific device name, I can confirm exactly which category it falls into.