So like 10 years ago, I did the thread on NWP on how to hack the Wii to play backups.

Again, I'm going to be a thorn in Ninty's side - here is all you need to play backups on a 3ds/2ds.

(At time of posting, this will work on all firmware revisions on all newly bought consoles)

First off, get yourself a Sky3ds -

Then get yourself a Micro SD card. I've tried a few, Sandisk 32gb's seem to be the ones that haven't failed me when using this.

The instructions on how to use the card are on the link above. Essentially, you use the diskwriter software to format the card to a format the 3ds can understand, and then use that to dump the roms onto it.

Finally, you will need some games -

Make sure you download the rom for your region!

Once that's done, slap the card in the Sky3ds, and then put that into your game cart slot. Press the button (or buttons, depending which version you buy) on the Sky3ds to cycle through the games.

You can use this to play online multiplayer as well if you wish, as Sky3ds has built in "stealthmode"