: I tried it out on Steam Half-Life on our new Intel Mac and I couldn't get it
: to work, but this could be because I don't even know how you are supposed
: to install mods on Half-Life.
Unlike source mods, which have their own directory structure seperate from the HL2 game files, HL1 mods go directly into the game directory. All you need to do is extract the rampancy.zip file into the half life game directory (steam\steamapps\your@email.com\half-life), restart steam, and it should show up in the games list.