Re-run the d2x cIOS Installer program to verify slot installations on 249 and 250.
In the context of Super Smash Bros. Brawl , a .wad file might be used for:
When you download a game from the Wii Shop, you are essentially downloading a WAD file. This file is then "installed" by the console, placing a new channel on your Wii System Menu that you can click to launch the game. Internally, a WAD file is an encrypted archive containing several component parts (certificates, a ticket, a title metadata file (TMD), and the actual data content in .app files). Super Smash Bros.brawl.wad
You almost certainly want an RVZ or ISO file for Dolphin, or a WBFS for a real Wii. The Super Smash Bros. Brawl.wad file you find on ROM sites is likely just an ISO that has been renamed incorrectly.
These are homebrew applications run from the Homebrew Channel. They scan your SD card for a folder named wad and safely write the contents to the Wii's internal memory. Re-run the d2x cIOS Installer program to verify
So, why does the file exist? Because the emulation community repurposed the term.
System operating files required for the Wii to run specific hardware or games. This file is then "installed" by the console,
Most mods come with a specific .wad file (often named something like Legacy XP Launcher.wad ).