Why Does an "Action Replay DSi" Exist If the DSi Only Plays DS Games?

The premise contains a misunderstanding: **Action Replay devices are not made *by* Nintendo for the DSi.** They are **third-party cheat cartridges** manufactured by companies like Datel. Here's why they exist for the DSi:

1. DS Games Still Run on DSi

The DSi is **backward compatible** with almost all physical Nintendo DS cartridges. Action Replay DS/DSi units are **DS-mode flash carts** that plug into the DS cartridge slot. They patch DS game code in real-time on the DSi (running in DS compatibility mode).

2. DSi Has No Native "Action Replay" Support

• DSiWare (digital games): Cannot be modified by cartridge-based cheat devices.
• No GBA Slot: Unlike the DS Lite/Phat, the DSi cannot run Slot-2 devices (often used for homebrew/cheats).
• System Updates: Nintendo patched the DSi firmware to block known flash carts (including Action Replay). Later DSi/3DS firmware versions require updated cart firmware (cat-and-mouse game).

3. The "Action Replay DSi" Product

Datel released updated carts (e.g., Action Replay DSi/3DS) with firmware that bypassed Nintendo's blocks. They still only cheat **physical DS cartridges**. They do not work on DSiWare, 3DS games, or the DSi menu.

Summary

Action Replay exists for DSi because **millions of DS cartridges are playable on DSi hardware**, and cheat manufacturers want to sell to that audience. It is not an official Nintendo product, and its functionality is limited to DS-mode cartridge games.