Ocarina Cheats in USB Loader GX — Codes, .gct Files and Per-Game Settings

Ocarina is the cheat engine built into USB Loader GX (and inherited from the original standalone Ocarina app): it applies Gecko-format cheat codes to a game as it launches, without modifying the game itself. Used well, it is how players unlock widescreen patches, remove nuisance limits, or revisit a favourite game with a twist. Used carelessly, it is also how saves get corrupted and online accounts get banned. This guide covers the whole GX workflow — turning Ocarina on per game, getting codes from GameTDB, generating the .gct file GX actually reads, and the one etiquette rule that is not optional.

Ocarina settings in GX are per game by design. There is no sensible “cheats on for everything” workflow, and this guide will not give you one: codes are written for a specific game, a specific region, and often a specific revision. Confirm your loader is current from the Download page first, and treat the Setup Guide as the baseline install this page builds on.

How Ocarina Works in GX

For each game, GX can hold a cheat file in the Gecko .gct format — a compiled bundle of codes. When you launch a game with Ocarina enabled for that title, GX loads the .gct and the codes take effect in memory for that session only. Your backup image is never altered, and disabling Ocarina returns the game to stock behaviour completely. Codes themselves are distributed as plain text lists (the .txt form), and GX contains a code manager that can download the text file for a game, let you tick individual codes, and generate the .gct from your selection. That generated file — not the text file — is what gets applied at launch.

Step-by-Step: Adding Cheats to a Game

1. Select the game in GX and open its individual settings. Ocarina is configured per title: choose the game, open Game Load / game settings, and find the Ocarina option.
2. Download the code list. With the console online, use the Ocarina / cheat management option for that game (GX offers to download cheats for the selected title). GX fetches the code list for that game’s ID and region from the cheat database mirrored alongside GameTDB — the same service family that supplies your covers and game info (see covers and GameTDB).
3. Choose codes deliberately. In the code manager, enable only the codes you actually want. Codes that conflict with each other — two codes writing the same behaviour differently — are a common cause of freezes. If you are troubleshooting, one code at a time is the rule.
4. Generate the .gct. Save/apply your selection in the code manager. GX writes the compiled .gct file into its cheat storage (the codes location within the GX data folders on SD/USB, named by the game’s ID). If you manage cheats on a PC instead, place a ready-made .gct with the game’s ID as its file name in that same codes folder — GX only looks for the .gct at launch time, regardless of which side created it.
5. Turn Ocarina ON for that game. Back in the game’s settings, set Ocarina to On. This switch is separate from having a .gct file: a file with the switch off does nothing, and the switch on with no file does nothing either. Both halves are required.
6. Launch and test. Start the game and confirm the code’s effect. If the game freezes before or at launch, the first suspect is a bad or conflicting code — disable codes in halves until the culprit shows itself. If everything freezes, turn Ocarina off for that title and confirm the stock game still runs; that separates a cheat problem from a game problem.

Where Codes Come From, and Region Discipline

The code lists GX downloads are community-maintained Gecko code lists keyed to each game’s ID. That ID encodes the region — a code written for the US release of a game generally will not work on the European release, because the game’s memory layout differs. If a downloaded list produces no effect at all, a region mismatch is the likely reason, not a broken loader. Likewise, some codes exist in versions for different revisions of the same game. The fix is always the same: match the code list to the exact ID of the backup you are launching, which GX shows in the game’s information.

Keeping Cheats from Hurting Saves

Codes that alter inventory, currency, unlocks, or progress write those changes into your save when the game saves. That is sometimes the point — and sometimes a nasty surprise when a “fun” code corrupts a long-running file. Before experimenting on a save you care about, back it up (save management is part of the wider GX feature set; see also the save-path discussion in our EmuNAND guide for how GX separates save locations). And treat any code that promises online advantages as what it is: a way to get banned, not a feature.

Frequently Asked Questions

I downloaded cheats but nothing happens in game. What is missing?

Usually one of three things: Ocarina is not switched On in that game’s individual settings; the .gct was never generated from the text code list (tick codes and save in the code manager); or the codes are for a different region/revision than your backup. Check them in that order.

Where does GX store the .gct files?

In the codes folder inside the USB Loader GX data folders on your SD card or USB drive, with each file named by the game’s six-character ID (for example RMCE01.gct). If you build a .gct on a PC, it goes in that same folder with that same naming.

Can Ocarina codes damage my game backup?

No — codes act in memory for the session and never modify the backup file. They can, however, affect save data if the game saves while a code is altering values, and they will get you banned if used online. Back up saves you care about and keep Ocarina off online.

Related Guides

• Covers and GameTDB in USB Loader GX
• Wiimmfi in USB Loader GX — Online Play
• EmuNAND and WiiWare in USB Loader GX
• Nintendont in USB Loader GX — GameCube Setup

New to the loader itself? Start with the USB Loader GX Setup Guide hub and get the current files from the Download page.