Portals are a pretty good idea as an addition to Brikwars; I have thought about using them, but I usually forget about them when I set up the battlefield.
Personally, I prefer portals of the non-mobile variety. If my troops are going to carry big heavy implements into battle, rocket launchers, flamethrowers and miniguns go a little higher on the list than portal-guns.
There could be three or more teams in a free for all with portals around a flag or something, you're safe if you're on your side of the portal and the objective can be to get the flag to your base, and you get a certain amount of men per turn
Blitzen wrote:To implement an actual Portal-style portal gun, I'd have a minifig be able to shoot it twice in a turn, then move. That way you can take full advantage of the potential mayhem.
I would actually say only one portal per turn, so that at least one of the previous ones stays open, and then all teams get to plan their strategies around open portals for a full round-and-a-half. Keep in mind that you can look and shoot through them, on top of just walking through.
A portalgun would be an idea, imagine putting one end of the portal on the barrel of a tank, then the other end into the valuable machinery of of your opponent.
suddenly a portal gun could be used to gaurantee hits with very powerful guns.
whether thats good or bad i'll let you choose.