Considering the... air alert "thing", I think simple is probably the way to go with new alerts. And this is somewhat simple. This is probably an idea for a meltdown alert. Instead of capturing territory, captures work a bit differently. Base capture rules work mostly as normal, initially, you can only capture bases to which you have a link. But. Instead of capturing, when you lose a base, it goes neutral and shuts down. After this initial set of captures, you can attack any base linked to a neutral area. Normal link-requiring reinforcement rules apply, but you can attack any base linked to a neutral base, anywhere. You can't use the captured bases for anything, you still have to pull from normal bases. If you lose tech, you have to pull tanks from warpgate. Construction bases operate normally. Bonus idea: Change capture speed based on empire ownership. As an empire owns less and less, they capture territory FASTER. So if you knock someone down, they get MORE dangerous. This could be based on total ownership, so the alert finishes fast? Or by relative ownership. It would speed things up and make it very interesting, because a faction beat back to their warpgate could nuke enemy territory REALLY fast if they can get there. Whoever has the last territory wins. If you get warpgated, you get knocked out of the alert. You have to warpgate the other guys to win, and if you knock them back, they might gal drop you on the ever-increasing neutral lines, and knock out bases before you can react! And construction bases would be VERY interesting, as a vehicle spawn system,
