A strange and crazy idea occurred to me today. It's been suggested that mines might be used in battle, placed in defense around a system, but what if you could put mines in a system that doesn't belong to you? Let me explain:
A type of cargo ship could be built, possibly containing troops, possibly containing fuel, and possibly containing mines. If a cargo ship carrying mines reaches a system that is not occupied by hostile ships, the player will have the option if deploying all, some, or none of the mines on to the system. If the player chooses to deploy mines, he will be given a view of the battlefield for that system and can deploy mines anywhere in the system.
If another player comes to that system, he will be alerted to the presence of mines in the system and have the opportunity to search for them and destroy them. If he wishes to proceed to a system beyond the mined system or colonize a planet within the system, it is not optional; he MUST pass from point A to point B within the system battle map with as many of his ships as is necessary to complete his goal. This is not as easy as it sounds, however, since the mines will have the highest cloaking technology available to the empire that deployed them, as well as a significant stealth bonus of their own.
If two fleets battle within the minefield, only fleets belonging to the empire which deployed the mines or an empire allied to that one will be able to see the mines initially. Any other fleets must be able to detect them as though they were any other object.
The reason I decided to post this idea is that such a feature would provide excellent strategic value. For instance, you could use mines to cut of a strategic choke point if your fleets are engaged elsewhere. You could protect the planets of your allies without actually risking your ships. You could protect a good planet from being colonized while you hurry to build a colony ship. Plus, who could resist wreaking total havoc by laying a bunch of mines and getting the heck out of there when two opposing fleets are on their way to the same system inside a nebula?
(providing nebulae increase stealth bonus, of course.
At any rate, a few details of my idea might be somewhat impractical, but I hope this kind of thing gets implemented in some way.
Sorry if something like this has already been suggested. I didn't see anything at a glance on the first 5 pages of this board.