Elemental will have two multiplayer options: connect to an SD server or connect to a "custom" server.
The host would have to create (and setup) the server, including any mods/maps. Any players who join will download the mod/maps from the server and play. Saves will be hosted automatically on the server (including SD's) but you can also choose to save them locally. This is mostly to make it easier to re-host games part-way through (instead of having to mail the save over to everyone).
Custom servers won't have any authentication (on SD's side).
So, if you were to wanting to ... "demo" this game to a friend to convince them to purchase the game (something I don't think Stardock would have an issue with, even if it is a violation of the agreement - especially if your friend do own their own copies of the game and just using your computer for convenience):
- If all the computers are on the same OS, you can use the method above (achive/unpack with Impulse)
- Or, you can actually copy Elemental onto a thumbdrive and copy it straight into Program Files. Then use Impulse, select "detect application" and then let it Verify the install (doing it this way you'll miss some key XML files, etc).
After both computers on the game on the computer, you'll run the server host (this may also be built into a nice little button in the game itself, we'll see. It sounded like Frogboy wanted to make the custom server hosting a little more sophisticated than most other games, and sophistication often times leads to complication which sometimes don't get nice, clean UIs), then you'll connect to your custom servers.