Contrary to what I've read in the few other posts on the subject I was able to find in this forum, Civ 3 Conquests is fully playable in Virtual PC on a moderately fast G4. The trouble is, there are a number of roadblocks on the way that have convinced some people it doesn't work.
Here's what you need:
1 copy of Windows '98. Why? Because it's way faster on VPC than any other version of Windows that can run Civ. A previous poster, who said that Civ 3 worked on his G5 but was unplayably slow also revealed he was using WinXP. Bottom line is, forget about XP for emulating Civ 3, it will slow everything to a crawl. Get Win98 somehow, it is quite zippy
1 copy of Virtual PC. I use 6.1, which seems to work fine enough on my 12 inch G4 iBook 1.2GHz, running Tiger. 7 is the most current version and may work better.
1 copy of Conquests, PC version. I used Civ III Complete.
Now that you've installed all this, don't forget to set your emulated PC to 1024x768 resolution and thousands of colors or you won't be able to run civ. Set VPC's RAM and VRAM usage to the max it can efficiently handle on your system.
Now, comes the part that shoots many people down. The Conquests game disc has SafeDisc protection, which is intended to prevent PC users from copying games. Trouble is, this protection renders your Conquest disc unplayable on your emulated PC, even if it is a 100% legit disc!
Moderator Action: This site does not condone the use, distribution or promotion of No CD patches.
Please read the forum rules: http://forums.civfanatics.com/showthread.php?t=422889
Now don't expect it to be at all fast, unless your computer is significantly better than mine, which it may be. You may want to turn off music, some animations, and maybe even sound. But it is at least playable on my iBook, and I am now a much happier Civ nerd. May this information prove useful for many Mac Civ fans as it has for me.
Here's what you need:
1 copy of Windows '98. Why? Because it's way faster on VPC than any other version of Windows that can run Civ. A previous poster, who said that Civ 3 worked on his G5 but was unplayably slow also revealed he was using WinXP. Bottom line is, forget about XP for emulating Civ 3, it will slow everything to a crawl. Get Win98 somehow, it is quite zippy
1 copy of Virtual PC. I use 6.1, which seems to work fine enough on my 12 inch G4 iBook 1.2GHz, running Tiger. 7 is the most current version and may work better.
1 copy of Conquests, PC version. I used Civ III Complete.
Now that you've installed all this, don't forget to set your emulated PC to 1024x768 resolution and thousands of colors or you won't be able to run civ. Set VPC's RAM and VRAM usage to the max it can efficiently handle on your system.
Now, comes the part that shoots many people down. The Conquests game disc has SafeDisc protection, which is intended to prevent PC users from copying games. Trouble is, this protection renders your Conquest disc unplayable on your emulated PC, even if it is a 100% legit disc!
Moderator Action: This site does not condone the use, distribution or promotion of No CD patches.
Please read the forum rules: http://forums.civfanatics.com/showthread.php?t=422889
Now don't expect it to be at all fast, unless your computer is significantly better than mine, which it may be. You may want to turn off music, some animations, and maybe even sound. But it is at least playable on my iBook, and I am now a much happier Civ nerd. May this information prove useful for many Mac Civ fans as it has for me.
I've never read anything about playing the Civ3 through VPC that suggests the user enjoyed the experience. But, that is how discoveries occur. Push on, my man! 
