Back when we last discussed this I believe it was supposed to be setup so that you would need at least three cruisers to take a mining colony and in the exchange they would lose one cruiser.
Zark said in this beta it would take at least a dreadnaught or equivalent Battlecruisers/cruisers to take a mining colony. That is something like 10-11 cruisers.
--- *Member of the SCAT alliance* ---
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