SMAniaC requires Alien Crossfire.
Extract SMAniaC into your main SMAC directory. Personally I have a special duplicate SMAC directory for SMAniaC besides the unmodified SMAC one. Others who don't have harddisk space to waste use
ModMan.
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I'll post the contents of the different readmefirst files here:
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customfac readmefirst.txt
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To get them to work:
Copy the contents of the seven folders into your main SMAC directory. Except for atlantis.mp3 and templar.mp3. Those should be put into the 'voices' directory.
Oh don't forget: you need to copy the alphax.txt included in this download over the standard SMAniaC one to be able to play these factions.