Firmware is required for games that call upon system menus, such as the Mii editor or keyboard.

Newer games or updates (NSPs/XCIs) released after May 2023 may require the encryption protocols found in version 16.0.3.

While Yuzu can run many games using only "prod.keys," some advanced titles and system functions require actual firmware files to operate correctly.

The release of Nintendo Switch Firmware 16.0.3 in May 2023 brought important system stability updates. For users of the Yuzu emulator , keeping your firmware updated is often necessary to ensure compatibility with the latest games and to fix specific emulation issues, such as the "Mii selection" crash in titles like Mario Kart 8 Deluxe . Why You Need Firmware 16.0.3 on Yuzu

Emulating the official system environment can resolve random crashes during the main menu or loading screens. How to Legally Obtain Firmware 16.0.3

To stay within legal boundaries, you should from your own modded Nintendo Switch console.