Just like a normal wargame, only you choose the shape of the arena from the following list: Celestia, Nil, Earth, Water, Faethorn, Etherglom, Etherseren, PrimeGlom, PrimeMagnagora, PrimeCelest, PrimeSeren, Astral.

Sounds like it needs to be an arena in a super-techno-city (holodeck?)

Lusternia has holodecks. They're just called stages.

I think this'd be interesting - I was actually contemplating making a manse back then which'd be an exact copy of Celestia for the purposes of practicing my running around.

Though when I first read the thread title I was thinking more along the lines of Alexander the Great, flanking and other interesting formations instead of just having the bigger group with more demigods.

In that light, SQUAD FORMATION felt like it could be better.

Yep. The idea is to practice running around and raiding a specific location without needing to actually go there and raid it for real.

This is a wonderful idea, though the ethereal forests are much too big for a wargame. Have one side designated as the attackers and the other as defenders, and have the option of allowing defenders to summon guards, use discretionary powers, or anything else really that could further simulate a raid.