Will US Games Work on a UK Action Replay DSi? No—Region Locked

Nintendo DSi and DSi Action Replay cartridges are region-locked:

• UK DSi only plays European (PAL) games.
• US games are NTSC region and won't boot.
• Action Replay cartridges are also region-specific.

Solution

Use a US-region DSi console to play US games. Region-free mods exist but void warranties and may violate terms of service.