The reliance on Title Keys largely depends on the format of the game files being used. The Wii U emulation community generally deals with three main formats: Game File Format Description Requires Title Keys in Cemu? Raw or compressed full disc rips.
The file follows a simple [Key] # [Comment] structure: cemu wii u title keys
CEMU looks for a file named keys.txt in two places: The reliance on Title Keys largely depends on
Decryption keys for Cemu are required to run encrypted Wii U game files, typically in typically in Historically
Historically, users had to manually find a "keys.txt" file online, paste it into their Cemu directory, and hope the keys matched their game dumps. This led to version mismatches, corrupted saves, and a general headache.