Action Replay Codes for Final Fantasy IV (DS)?

No reliable Action Replay codes exist for the DS version. Square Enix implemented anti-cheat measures (checksums, encrypted save structure) that cause the game to freeze or delete the save when modified code is detected. The Action Replay DS hardware is also incompatible with DSi/3DS enhanced cartridges (which FFIV DS is).

Legitimate Alternatives

• Grind efficiently: Fight in the Lunar Ruins (post-game) for massive EXP/gil.
• Augments: Transfer abilities between characters via the Augment system (talk to NPCs in each chapter).
• New Game+: Carry over levels/equipment for easier subsequent runs.
• PC Port (Pixel Remaster / 3D Remake via emulator): Use built-in boosters (×4 speed, no encounters, god mode).

Enjoy the story and strategic depth—the 3D remake was balanced around fair play.