Introduction New Super Mario Bros. Wii (NSMBWii) is a popular 2009 Wii platformer. A “WAD file” in the Wii homebrew/modding scene commonly refers to a packaged file format used to install channels, games, or system content onto a Wii via the Wii’s IOS/Disc channel system. Examining “New Super Mario Bros. Wii WAD file” therefore involves technical, historical, legal, and security perspectives: what the WAD format is, how it relates to NSMBWii, typical uses in modding, the structure and tooling, and the risks and legal considerations.