What is a CDTC file? A CDTC file is a game data file used by Super Mario Maker for 3DS, a Super Mario level creator available for the Nintendo 3DS handheld gaming console. It contains binary course data specifying a user-created level, including objects, tiles, power-ups, and player and enemy placement. CDTC files also store settings and metadata , such as when the level was created.

More Information Super Mario Maker for 3DS is similar to the Wii U version of the game, allowing players to create and play their own Super Mario levels. The Wii U version saves course data as .CDT files and the 3DS version saves course data as CDTC files. The second "C" in the file extension likely refers to "CTR," the internal hardware model codename for the 3DS platform. The proprietary CDT and CDTC formats are similar but not interchangeable. For example, the Wii U version of Super Mario Maker does not support CDTC files, and the 3DS version does not support CDTC files. Also, the CDTC format is compressed to adhere to 3DS requirements.