Wolfenstein 3D Data Format was developed by id Software. WL1 files store game data for the shareware version of Wolfenstein 3D. The format is compatible with software installable on Windows. WL1 files are categorized as Game Files. Files can be copied to other devices, but may not open properly.
Wolfenstein modding programs allow extracting game data from WL1 files. For example, SLADE and Havoc’s Editor can open them. To open a WL1 file, first install a program supporting the format. If installed but not set as default, right-click the file, choose open with, and select the program. Check the box to always use that program.
For Mac users, double-click the file to try opening it. If unsuccessful, ensure Wolfenstein 3D is installed. That associates WL1 files with the game. Websites detail Wolfenstein 3D and WL1 format. The game maker’s site has info. WL1-compatible programs are listed there too. Conversion to other formats is not possible.