The Source engine typically looks for a sourcemods folder within the Steam directory to load fan-made content. However, for standalone or "repacked" installations, the engine can be manually directed to load a mod folder using the -game command. 1. Core Technical Requirements
If your mod fails to launch, diagnose with these fixes: half life 2 mods non steam repack
Inside that substance folder, you should see maps , materials , scripts , and a gameinfo.txt file. The Source engine typically looks for a sourcemods