Only one Animal Crossing: New Horizons island can exist per Nintendo Switch console no matter how many accounts are registered or copies of the game owned, Nintendo has confirmed.
"Please note: only one island can exist per Nintendo Switch console, irrespective of the number of user accounts registered to or copies of the game used on one console. One Nintendo Switch and one copy of the game is required for each unique island."
This is how previous Animal Crossing games worked on Nintendo's past hardware, but there was some hope among fans that things would be different on Nintendo Switch, which supports multiple users.
Nintendo's fine print does not explain this situation, or offer any clue as to why it must be the case. Could there be some security risk? Is this Animal Crossing save data any more valuable than any other save data that does not have this limitation? Or perhaps the decision is largely philosophical. Animal Crossing is all about sharing the same space as your family, as its creator, Katsuya Eguchi said in a 2006 interview with Gamasutra:
"Another thing is that I'd always get home really late. And my family plays games, and would sometimes be playing when I got home. And I thought to myself - they're playing games, and I'm playing games, but we're not really doing it together. It'd be nice to have a play experience where even though we're not playing at the same time, we're still sharing things together. So this was something that the kids could play after school, and I could play when I got home at night, and I could kind of be part of what they were doing while I wasn't around. And at the same time they get to see things I've been doing. It was kind of a desire to create a space where my family and I could interact more, even if we weren't playing together."
Nintendo points out that up to eight players with registered accounts on a Nintendo Switch console can live on one shared island, and up to four residents of one island can play simultaneously on one console. But if you buy Animal Crossing: New Horizons and you want someone else to play the game on their own island, you have to buy another copy of the game - and another Nintendo Switch.