This is the hardest and most annoying to use exploit. You will need a computer with Linux, any version of Smash 3DS (you can try the demo too), a compatible router (no easy way to check this, just try it and see if it works), and plenty of patience. I would only reccomend this if you have secondary hax availible (Menuhax, OOThax, etc.) and no way to install it. It works on 9.3-10.3.

 

 The full game still works on the latest update (1.1.2), but the demo got a patch in november 2015 which fixed it. If you downloaded the demo beforehand, it will work, just don't update it ever, if you do accidentaly update it, you can just delete the update.

 

 Since I don't have Linux, this hasn't been tested yet. It will be in the near future. For now, try to use this guide.