If any of those CDs require internet to install, they must have been later releases during the dying era of CD game installs. I have original CD copies of all AOE games and they dont need any internet at all.

I’ll have to get back to you on exactly which one I have and how it reacted offline. I just discovered that AoE is still making new releases every year. You must be spending a fortune if you have every single AoE game ever released. Or if you have dodgy versions, then those could be internet-independent due to crackers.

Using dd is important as you can flat dump every single bit out of the CD, including the hidden license information.

The fact that dd has no smarts about the media is exactly why it’s a problem. The copy protections are designed to ensure that bit-by-bit copies fail to work. They insert some kind of optical ”defects” which force drives to do some kind of error correction. A copy (image or physical CD-R) has a copy of the bits but not the defects, so there is no error dection/correction activity, and that’s how the game knows it’s not a factory disc.