Can someone explain the logistics of modding my 3DS?

[Kitten of the Broccoli]

I just bought a New 3DS XL(used, lol) yesterday, and I'm looking into the whole modded firmware thing with it. It seems simple enough to do, but is there anything I should know beforehand? For instance, what exactly would cause Nintendo to block my system from accessing the Nintendo Network? How likely is it that I could permanently brick my system? Is there a way to revert back to the stock firmware should I find myself needing to do so? And, I guess most importantly of all, what can I actually DO with a modded system besides playing unsigned games?

[Soneich]

This is a pretty good guide for putting custom firmware on the 3DS: https://3ds.guide/

 

You can brick if you mess up badly, but the guide makes it clear what mistakes will cause a brick.

I'm pretty sure you can revert to stock firmware, but I haven't looked into it.

 

You'll want to turn off spotpass and a few other things (I'd recommend looking up what to turn off to be sure) to prevent Nintendo from collecting system information and issuing a ban. No one can say for sure that this will 100% work, but I've taken the precautions and haven't gotten banned yet.

 

With custom firmware you can install custom themes, emulators, and whatever other homebrew apps are available out there.