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For preliminary reading or if you have any questions see the 3DS Hacking FAQ, if you absolutely have to post your question post in this thread - 3DS - Ask questions here


The Blue Card is used for installing Gateway and running DS games/homebrew. The Red Card is used for running 3DS games/homebrew.

Things that will be used in the installation:

  1. The Blue Card from Gateway.
  2. The microSD card used in the Blue Card, a larger microSD should preferably be used for the Red Card since 3DS ROMs use much more space.
  3. The SD card that the 3DS uses for user data.

Copying Files and Backing Up Data

Format the microSD card you plan to use in the Blue Card as FAT32 (Right Click -> Format -> File System) Download the latest Gateway firmware off the Gateway website or a mirror.

After uncompressing the Gateway firmware copy everything inside "Blue Card (R4i)" to the root of microSD you plan to insert in the blue card. Backup the entire SD card onto a computer, then copy the file Launcher.dat to the root of the SD card

Using the Gateway Installer

Insert the blue card in the 3DS and run the Deep Labyrinth app (Sword Icon) that appears, this should open up a file explorer for your Blue Card's storage, navigate to the Gateway Installer, execute it and follow the instructions. The installation may sometimes hang, hold the power button to switch off the 3DS and try again If installation succeeds follow the power off prompt. Gateway is now installed.

Entering the Gateway Menu, Backing up your sysNAND and creating an emuNAND

Switch on the 3DS, enter the Settings menu, then the Other Settings menu, the Profile Menu and finally hold the L button while pressing Nintendo DS Profile button. The Gateway logo then the Gateway menu should appear if not, power off the 3DS and try again.

Choose the backup NAND option, this will take a while. After the backup is done power off the 3DS and then copy the backup (NAND.bin) to a safe place. You may delete the backed up sysNAND from the SD card.

Enter the Gateway menu again as shown above, this time choose the format emuNAND option. This will wipe your entire SD card and create emuNAND that Gateway Mode uses. If you need to move back your user data to the SD card do this now. You are now ready to use emuNAND.

Basic Usage

The following actions will make you exit Gateway mode, meaning you have to reenter through the profile exploit.

  1. Entering settings while in Gateway mode or Gateway Classic mode.
  2. Switching off the 3DS or running out of battery.

You will need to run the Gateway installer every time you use the blue card's app (to run DS games/homebrew)

3DS (Red Card)

Enabling Online in 3DS Games

Note: Your old saves will not work after you enable online in a particular .3ds file.

A select few games will also require updates to function (e.g. MK7 and Pokemon X,Y) if the current Gateway firmware does not allow eShop access then the only way to get these game updates is to update the sysNAND, download the needed game updates then with a hardware mod restore yourself to 4.1-4.5 using your sysNAND backup. ROMs from release groups nearly always have their header missing, to allow online functionality you will need to inject a header from a retail game dump into the .3ds file.

A header has the following information in it:

  1. Cart ID - This is an ID unique to the particular cart it originated from.
  2. Chip ID - This holds information about the manufacturer of the cart, the capacity and the card type. The Chip ID is the same for all copies of the same game.

The Cart ID needs to be legitimate for the header to allow online play. Cart IDs from other games may be used in ROMs as long as the Chip ID is also correct. You can either inject this header that has been shared publicly - CTR-P-AMGJ.bin or inject your own private header from your own retail cart dump. It is not know at the moment whether Nintendo can detect identical Cart IDs going online at once or/and whether they will take steps to ban users/blacklist cart IDs, although from looking at the past Nintendo has never resorted to banning users.

To inject a header into your .3ds file use Gateway Rom Patcher 0.6

  1. If you want use your own header file with its unique Cart ID you must first make a dump of any your retail carts and then load the dump then using the patcher export the header.
  2. Open the patcher and load your .3ds file.
  3. If you do not want to backup your .3ds file uncheck "Ask to create a ROM backup before patching" otherwise you will be nagged every time you import or inject a header.
  4. Import either the public header found here or your own header.
  5. The program will ask whether you want it to correct the Chip ID if it does not match, always press yes.
  6. Finally inject the new header into your file, exit the patcher and change the extension of your game from .3ds to .3dz
  7. Copy the game to red card and you can now use the online functions.

Running 3DS Games/Homebrew

Format the microSD to be used in the Red Card as exFAT and copy the .3ds files over, insert the red card into the 3DS. Enter the Nintendo DS profile without holding L and it will automatically boot you into Gateway mode, you should now be in Gateway mode running emuNAND. Press select and this should bring up the 3DS games/homebrew menu, use the D-pad to select your application.

Reordering the 3DS Games Menu

Use this to sort the .3ds files - FAT Sorter

Play Coin Generator

Run this .3ds app - PlayCoinSetter.3ds

DS (Blue Card)

Running DS Games/Homebrew

Insert the blue card and run the Deep Labyrinth app, simply navigate to the DS file using the file explorer and press A.

Using Cheats

You may update or edit cheats database file that is bundled with blue card at /_rpg/cheats/usrcheats.dat. While having the game you want to cheat in highlighted press Y and then X for cheats, remember to press A to save and exit.