Only 7/8 years ago we were learning to Mod CivIV, there were no illegal hacking Streams there. This and a few other independent forums is were most communicated and exchanged mods. 100,000 FFH games were downloaded like this 25,000 Rhys and Falls etc.
the practice was and still should be:
1) Download a Mod from the Data base here.
2) Open a folder under documents anywhere else except near the Civilization Folders, and call it MyMods, under which you copy the Download as well as a note to yourself of how to use it using Notepad or any such app.
3) Now copy the zipped or opened Mod folder under Civilization 5 or other reiteration of the game you're playing in that ones Documents/{user}/Civilization 5/ MOD folder.
4) My experience is play offline forget the stoopid cheap "wins" the Steam offers, and if you want to go online for whatever reason, cut & Paste your balanced MOD folder onto your desktop, and create a new Folder called MOD in it's place, leaving it empty.
5) Sure enough you'll get every single Mod you have ever subscribed for re-downloaded from Steam.
6) If you're not interested in the Steam scoring and prizes, that's it after the downloads pick the Mods you want and copy them to your useful folders, take the one that's full of unwanted mods and delete it. Go offline, replace your working MOD file and play. What requires more than a grain of common sense?
OR
If you can't live without winning the prizes, then learn to Mod the base files while keeping copies of the originals in another Folder. (That's how CivIV is modded anyway) give yourself the best handicaps build everything beat everyone etc. Then replace all your modded files with pristine new ones and without deleting your cache and with an empty MOD folder again, go back on line and be surprised by the kudos you'll get from the stoopid Stream Engine who'll read your cache but find no Mods!!! QED. Good Luck
