Just gonna throw in a few Q&A's in here for simplicity's sake, maybe
@Cyan might use some in the OP or something.
Q. Can I downgrade my 11.0.0-33 system without a hardmod?
A. Yes using the fieldrunners' dsiware hack, which requires the purchase of fieldrunners, there are
no other methods of soft downgrading right now.
Q. Can the 2DS be hacked?
A. Yes, the 2DS is for most purposes just an o3ds without a 3D slider. Most guides out there point this out, several times.
Q. Can I install DS games as CIA?
A. No, not unless they were DSIWare.
Q. How do I hack my 3DS/2DS/N3DS?
A. If it's below version 11.0.0-33 or if you have a nand backup of an earlier firmware, follow one of the many guides that you feel you're most comfortable with, most people just recommend following Plailect's guide.
Q. My 2DS says move the 3D slider up, but I have no 3D slider?
A. Good job, you formatted when you shouldn't have. You need to restore a nand backup, you're soft bricked.
Q. How do I update LUMA?
A. Either install luma updater cia and update using that or download the latest release and delete old luma files, replacing them with the new files.
Q. My _______ accidentally updated to 11.0.0-33. What do?
A. See the first question.
Q. I don't want to hack my 3DS I just want a flash cart, what is best for me?
A. Most everybody will just recommend a SKY3DS.
Q. I just want homebrew, can I run homebrew on 11.0.0-33?
A. Yes! You can find all of the relevant information
here.
Q. Aren't people just going to overlook this and ask the questions anyway?
A. Probably, but at least I tried.
Q. How do I cheat on my 3DS?
A. You can either go out and buy an action replay 3DS, which reads carts and modifies the save, or you can get a gateway and have access to a cheat engine by pressing select in gateway mode and choosing an in-game toggle, or you can downgrade your browser and use spiderAR, or you can use NTR plugins on NTR CFW.
Q. What is CFW and how do I get it?
A. CFW is Custom Firmware, the best way to achieve custom firmware is to follow a guide, such as plailect's guide, which uses luma cfw. This of course requires a version
lower than 11.0.0-33.
Q. My A9LH 3DS makes a pop noise and turns off right after I turn it on, is it broken?
A. Probably not, make sure you have the arm9loaderhax.bin file on your sd card and if you're using luma, the luma folder + payloads. Or maybe you just tried to turn your 3ds on without the sd card in, so put it in. Else - further troubleshooting is required.
Q. Is it safe to play online with CIA's?
A. Yes. Unless you cheat, then you probably deserve to get banned.
Q. Should I install gateway "fastboot"?
A. No, use the community alternative A9LH, you can boot into gateway using their payload anyway, so you don't lose your gateway features. If you installed gateway fastboot, your 3DS would only work with the gateway red card present and if it ever broke, you'd need to buy another in order to use your 3ds again.
Q. I have a JPN 3DS on 11.0.0-33, what are my options?
A. Pretty much, your only reasonable method to downgrade and get emunand/cfw is a hardmod, unless you happen to have one of the (legit-purchased) removed dsiware hax-able games on a JPN o3ds that is hacked so you can system transfer. Or if you just want a flash cart, see the flash cart question. Else if you just want homebrew, you can find information
here.
Q. I bricked my 3DS but don't have a nand backup, what do I do?
A. Cry and shake your fist at the heavens for your mistake, because there's no getting that back. Unless it's a soft brick and you can enter recovery mode to update to the latest version, which then becomes impossible to downgrade without an old hacked 3ds or a hardmod.