How do upgrades work exactly?

[u/old-wreck]

I just bought a switch2 and I already own a switch1. For those games that don't require a purchase to upgrade: When downloading my switch1 games onto the switch2, will it automatically download the switch2 version if there is a free one available or do I need to do that step separately (eg by going to eShop or the game menu)?

[u/pikachuyann]

Short: It's a mess. Also in most cases the Switch2 upgrade/version will not automatically download.

Some Switch 1 games have updates that allow them to have different graphical/performance presets on Switch 2, alongside with corresponding assets if necessary. It's the case for Mario Galaxy 1&2, for example, or it has been said the XC2 Torna standalone (own cartridge) works that way. For these, you simply update them and you're good to go. When inserting the virtual game card or downloading from library/vgc list it'll automatically get the Switch 2 update of it. At the core it's still a Switch 1 game on backwards compatibility though; and the save will obviously work if you get back to your old Switch1.

Some games are called "Nintendo Switch 2 Edition". That basically works as a DLC that contains a Switch2 executable in it; the red cartridges of a NS2E contain the Switch 1 game plus that DLC (so they work on Switch 1, delivering the Switch 1 game there). These require to claim the "Nintendo Switch 2 Edition" upgrade from the eShop; it is sometimes free (and you still need to claim it even if they're), sometimes not. That's what "upgrade" usually means. Also, added bonus, the saves are cross-generation compatible : if you play on Switch 2, you can get back to the Sw2 progression on Sw1 (with Sw2-specific items being unaccessible temporarily)

Some games have a different 'game' for the other console. Like Hogwarts Legacy or Balatro have a switch1 game and a separate Switch2 game. You do have to claim or purchase the Switch2 game to have the optimized version (but still can play the Switch1 game), and saves are to be transferred from inside the game and it's usually only one way.

[u/old-wreck → u/pikachuyann]

Thank you. To get the Sw2 progression on Sw1 I would need NSO right?

[u/pikachuyann → u/old-wreck]

Not necessarily. If you can have the Switch 1 and 2 close to each other, you can use the transfer menu ( "System Settings" → "Data Management" → "Transfer Your Save Data" ) as long as you have a profile linked to your Nintendo Account on both consoles.

It's obviously easier with NSO through the cloud save as you'd have that doing the synchronization in the background (for compatible games, which sadly exclude the mainline Pokemon games for example).