There are 2 file types use the .WAD file extension:
1. Nintendo Wii Game Data File
A WAD file is a game data file used by the Nintendo Wii game console. It contains the data required for installing Wii channels, system menus, or firmware updates. WAD files are often used for installing genuine copies of Virtual Console (VC) games.
NOTE: WAD files are also used by "Homebrew" Wii developers to install and play games.
Updated: July 6, 2020
2. Doom WAD File
A WAD file is a game data file used by Doom and Doom II, as well as other first-person shooter games that use the original Doom engine. It contains data such as sprites (graphics), level information, and items. WAD files are used for storing original game content as well as game modifications.
You can open, view, and edit a WAD file with SLADE, a free, multiplatform DOOM modding application. However, if your WAD file is saved as a Half-Life package, you may have to selectand save the file as a WAD2 file to keep your edits.
Updated: February 16, 2020