“So key cards will start up on the console or system that it is slotted into, so it’s not tied to an account or anything,” said Sasaki.
That behavior is different from the Switch games that Nintendo currently sells in retail locations, which feature a download code instead of a physical cartridge. Those codes can only be used a single time and are connected to a specific Nintendo account, preventing them from being resold at a later date.
Game-key cards automatically trigger a game download when inserted into a Switch 2 console. Once the game is downloaded and installed, an internet connection “...is only required when you launch the game for the first time,”
according to a support page on Nintendo’s website. After that initial launch check the game can be played without an internet connection, as long as the game-key cartridge is still inserted into the console.