NTR is a generally outdated plugin loader. However, it is still necessary to load older plugins in the .plg format. The only way to load NTR on modern CFW setups is using BootNTRSelector.
Launch Universal-Updater from the HOME Menu, or from the Homebrew Launcher
Select the magnifying glass on the bottom screen, then search for BootNTR
Press A while hovering over BootNTR from the list of homebrew
select BootNTRSelector.cia
If you are on an old 3DS and want to use plugins with extended memory mode games (such as seventh generation Pokémon games and Super Smash Bros.), also get BootNTRSelector_Mode3.cia as you will need to use it for such games
Select the magnifying glass on the bottom screen, then search for Luma3DS
Press A while hovering over Luma3DS from the list of homebrew
Choose boot.firm
Wait until the app(s) finish installing
Reboot your console
If you see the Luma3DS configuration menu, enable any options that you need, then press Start
Hint: If you don't know what the options are, you don't need them
If you are on an old 3DS and want to use plugins with extended memory mode games (such as seventh generation Pokémon games and Super Smash Bros.), also get BootNTRSelector_Mode3.cia as you will need to use it for such games
The latest release of Luma3DS (the Luma3DS .zip file)
Luma3DS v13.0 or higher is required to use BootNTR Selector (or 3GX loader for older versions)
Installation
Insert your SD card into your computer
Copy the BootNTRSelector .cia file(s) to your SD card
Copy boot.firm from the Luma3DS .zip to the root of your SD card, replacing boot.firm if it is already there
Reinsert your SD card into your console and power on
If you see the Luma3DS configuration menu, enable any options that you need, then press Start
Hint: If you don't know what the options are, you don't need them
Install the BootNTRSelector .cia file(s) using a CIA installer such as FBI
Using NTR plugins
Plugin location
If you're using the default configuration, NTR will look for plugins in the plugin folder on the root of your SD card. Each plugin must be inside a folder named with a game's Title ID. Inside the folder, place your .plg file.
You can get the game's title ID from here (cartridges), here (digital games), or from the FBI -> Titles menu. For example, Taiko no Tatsujin: Dokodon! Mystery Adventure's title ID is 0004000000190E00, so if you wanted to use a plugin for that game, you'd create a folder named 0004000000190E00
The creator of the plugin may have already created a folder with the correct name for you, in which case you can just copy the title ID folder from the plugin's zip/rar/7z archive to the plugin folder
If you want the plugin to run for all games (for example, for an FPS overlay), create a folder called game inside the plugin folder and place your plugin inside
An example directory for a plugin affecting one game would be plugin -> 0004000000190E00 -> plugin.plg.
An example directory for a plugin affecting all games would be plugin -> game -> plugin.plg.
Launching NTR
Open the BootNTRSelector app on your home menu
Select 3.6 on the version selection screen
Even if the plugin you are using says that it requires another version, try using 3.6 instead. Only use another version if 3.6 will not work
Launch a game that you have a plugin for. You should see a green flash upon loading the game - that means that the plugin is active
Look at the information on the plugin's webpage/README for usage instructions - usage will differ for each plugin
Usage notes
You cannot play more than one game with NTR without rebooting your console. When you are done playing a game, power off your console
You must launch NTR every time you wish to use a plugin
Certain applets, such as the New 3DS's internet browser, may crash if you try to open them while NTR is active
