I wanted to know how much you could do to Civ4. Can you only add new civs/units or can you completely change the game. Really, I'm asking if it is possible to use the engine or only the game. For example, could I change the way battle works? Or could I eliminate technology from the game? Is it possible to change the actual game rather than just what the game consists of?

Change the game as much as you want with the SDK. Unfourntuantly its not out yet, but will be as soon as the next patch comes out (which should be soon).

Sweet. My friends and I have a few ideas, including adding a tactics mode (like an embedded tactics game similar to FFTactics) and a stargate-like mod (with multiple planets).

I hope Spore ends up moddable as well.

For alot of things, you don't even have to wait for the SDK. Change battle? Work with the python scripts for battle. Add or remove techonologies? Work with the Technology XML file. Rebuild the enitre game from the ground up? Why not just code your own game? :)

I too am looking forward to Spore, and I hope it is as moddable as Civ4.

Rebuild the enitre game from the ground up? Why not just code your own game?

Because then I'd need to code an engine ;) With the xml this sounds very nice, but I don't know any python (I do know a bit of many languages, but the programming language I know well is php, though most are very similar so it shouldn't be too hard to learn). Here's a good question:

An idea my friend had and we plan on making is a tactics mini game. Battle in civ4 (and really any civ game) has always been pretty boring, since it really works how every other part of the game works: producing as much as possible while keeping economy working. There's no real strategy or anything, and the actual battles aren't controlled by the player at ALL. To do this, when you attack, it would open a mini-game of tactics, which would probably be similar to either tactics games (Final Fantasy Tactics), Heroes of Might and Magic, or some combination of the two. We've discussed and this would work with the addition of a few things, but I don't want to get in to it so no one steals the idea.

Is this possible? With or without the SDK I mean. I'm guessing I would need the SDK.

Hmm, that is actually a really cool idea. I think it would be possible with python. You might want to post the idea on the main Creation forum and see if anyone has any ideas.

Master of Magic has an isometric-view tactical battle system--and I love it to death. Considering it's not hard to imagine someone at the very least trying to recreate MoM once the SDK comes out, you might want to check out how that battle system works.