A common problem for Nintendo 2/3DS games is that they offer just one save game. I'm looking at you, Pokemon. If you want to start a new game, you need to erase all progress of the last one. This creates a problem if there is just one copy of a game, but several people who would like to play it.
If the game is on a cartridge, you're out of luck. But what about if you bought it on eShop and installed on an SD card? Can you take 2 SD cards (cheap these days), download the game on each of them (using the same console) and effectively get 2 save slots? Whoever wants to play just pops in their own SD card and continues where they left off?
Reading other answers here and on the Internet seems to suggest that this is possible, but I couldn't find any outright confirmation. Can anyone confirm if this works?
If it matters, my particular console is the New 2DS XL.
Best Answer
So, I have finally gathered my courage and tried this and can confirm - yes, this works! I now have two SD cards with the same game downloaded on both of them, and I can play them independently.
Update: Spoke too soon. While this does work with some (most?) games, others have protection SPECIFICALLY against this. In particular:
It appears that Ultra Sun stores an encryption key within the DS itself and regenerates it every time the savegame is deleted. Thus the old savegame on the other SD card becomes unusable.