I have a New 3DS XL and was wondering how best to record it; afaik capture cards aren't really a thing for newer 3DS' and when they do exist they are physical mods to the console. I'm also aware that you are able to soft-hack the 3DS' software to stream the game to your PC but I was confused by the wording on the EMU/NTR category on weather that means all NTR runs are included or if its Emulated games are recorded with NTR for legitimacy reasons.
You can do runs on the NTR category by using a softmodded 3DS and following the settings shown in the Rules section.
Alternatively you can run the game on a PC with the Citra emulator and capture the gameplay from it with a simple OBS game capture.
They're both in the same leaderboard because they're not considered original, unmodified hardware, which can only be accomplished with a hardmodded 3DS with video capture.
You can also record using a video camera like a phone or a webcam for the main leaderboards. Currently NTR and Emulators aren't split, as we do not have enough information regarding them, but may end up splitting those leaderboards as well. They both play faster than a normal console, which is why they have been separated from them.
