This app can damage your savegame if not used correctly. I'm not responsible of any data lost.
Be careful when editing your savegame, always keep backups of your savegame.
How to dump and inject AC:NL savegame
Requirements
a hacked Nintendo 3DS/XL, New Nintendo 3DS/XL, Nintendo 2DS or New Nintendo 2DS XL
retail/digital version of AC:NL with or without Welcome amiibo update
Follow this guide in order to hack your 3DS. This is a necessary step. You will only need to do this once.
The guide above will install a CFW (along Checkpoint) that allows to run unsigned code in your 3DS. This will allow us to run Checkpoint, which is a simple program that can extract AC:NL (and other games aswell) savegame then reinsert it after being edited with the editor.
Extract savegame
Open Homebrew Launcher
Open Checkpoint
Choose AC:NL icon and press A
Choose Backup (L) and type a name for the savegame backup
Power down the console, take out the SD card and put in the PC
Insert savegame
Browse your SD card and make a backup of /3DS/Checkpoint/saves/Animal Crossing New Leaf/[your_savegame_name]/ entire folder
Open /3DS/Checkpoint/saves/Animal Crossing New Leaf/[your_savegame_name]/garden.dat (or garden_plus.dat) file with AC:NL Save Editor and edit it to your desire
Save the edited town as /3DS/Checkpoint/saves/Animal Crossing New Leaf/[your_savegame_name]/garden.dat (or garden_plus.dat) in the SD (make sure you are overwriting the original file and not creating a copy)
Insert the SD card in the console
Open Homebrew Launcher
Open Checkpoint
Choose AC:NL icon and press A
Choose Restore (R) and select [your_savegame_name] folder
Run AC:NL and get ingame, your changes should be there!
FAQ
Will I be banned if I play online with a hacked savegame?
Yes, you might be banned from online functions if you change your TPC pic and use the Club Tortimer.
How can I rotate furniture in rooms?
Right click on the desired furniture then left click to rotate it.
How can I place perfect fruit trees?
Select the desired tree in the Current item dropdown menu, then choose Perfect 4 in the Flag 1 dropdown menu. You can even put non-native perfect fruit trees!
You can also place rare mixed perfect fruit trees (2 normal fruit+1 perfect fruit). Right click on any of your normal fruit trees in your town, choose 0x01 mixed perfect in the Flag 2 dropdown menu then overwrite it in the map (or whever you want to place it).
How can I move a building?
There are two ways to move a building:
Mouse over the map, the cursor will turn into a hand if the existing building in the spot can be moved. Click and hold, and move it to the desired location.
Buildings can also be moved manually by changing their coordinates in the building list, this allows to place buildings outside the playable area (the dock must be there). Additionally, you can press cursor keys in the keyboard instead of typing the numeric coordinates.
How can I add special characters to my name?
Choose a special character here:
and it will be copied to the clipboard Then paste it in the desired field.
I've injected Holden/Filly RVs, but they do not ask me to come to the town.
Both Holden and Filly are RV locked, so they cannot come to your town as villagers legally.
The only way to have Holden/Filly as villagers is to inject them directly into your town into an existing villager.
Your editor glitched my savegame!
No. It wasn't my editor, it was you.
The editor can do cool things, but it's also a dangerous tool and you are the only responsible while using it. Keep always a backup of your previous savegame.
If you think you've found a bug, post your feedback here.
Can I create building seeds like Wild World?
No.
What can I do to ensure my savegame does not get glitched?
there must be at least a pond,
there must be two waterfalls (wall and sea),
there must be a town plaza acre,
there must be two slopes: you can move them carefully using the acre editor
do not do weird things with the acre editor: try to keep a valid acre structure
keep at least two rocks: move them using the map editor if you need it (use right click to 'copy' the rock, place it anywhere then delete the original one)
keep enough free space for buildings in the town plaza acre: the game will freeze whenever special visitors (Redd, Gracie, Katrina...) try to put their tents there and there is not enough space
be careful when moving any building: you can adjust building placements with the editor, but don't do weird things like placing houses in the water
The game says my savegame data is corrupted. What happened? Can I restore my savegame?
That means you injected an old savegame, and the game blocked it using an anti-cheat protection system.
Do not worry, you can still restore it. You will need to update its secure NAND value.
Make a backup of your old savegame you want to restore
Restart your game and save. Make a dump of this new AC:NL savegame.
Open the old garden.dat/garden_plus.dat savegame in the editor
Go to the Other tab, click on the pencil next to Secure Value and load the newest garden.dat/garden_plus.dat here.
That will turn your old savegame into a valid savegame for the console.