Can You Use Mario Kart DS Hacks in Local Multiplayer? (No—And Why)

No. Using hacks (Action Replay codes, ROM patches, cheat databases) in Mario Kart DS local multiplayer:

• Desyncs the session: Deterministic lockstep netcode detects state mismatch → disconnect.
• Corrupts save data: Modified RAM values can write bad records to cart/NAND.
• Violates Nintendo Wi-Fi Connection ToS (defunct, but local wireless uses same protocol).
• Ruins fun for others: Infinite items, speed, invincibility = zero challenge.

Legitimate Ways to Spice Up Local Play

• Custom Tracks (Homebrew): Mario Kart DS Deluxe (ROM hack) adds 32+ custom tracks. Requires flashcart (R4, Ace3DS+) or Twilight Menu++ on DSi/3DS. All players must run the same patched ROM.
• House Rules: "No Blue Shell," "150cc Mirror Only," "Item Box Roulette."
• Time Trials + Ghost Swap: Trade ghost data via SaveMii / Checkpoint homebrew.
• Mario Kart Wii (CTGP Revolution) — 200+ tracks, 8-player local, active community. Better platform for mods.

If You Want to Practice Alone

Use No$GBA or melonDS emulator with cheat search to learn tracks, then transfer skills to hardware.

Play fair. The satisfaction of a clean 3-star Grand Prix beats any cheat.