AI War:No Warning On Waves?
Why Are Waves Coming In Without Warning?
Q: With AI players of difficulty 6 and up, the AIs have sometimes started sending waves to my planets without warning. Even the Advanced Warp Sensor isn't giving me any warnings. What gives?
A: If this is happening to you, then that means that you've destroyed ALL of the AI warp gates adjacent to all your planets. This is actually pretty hard to do, but if you manage it then this behavior occurs. On the lower difficulty levels, AIs in this situation will just reinforce their own planets rather than attacking yours. On difficulty 6 and up, they'll warp their waves into one of their planets (since yours are all inaccessible), and then send the ships they warp in through the wormhole chain to your planets. Since they aren't warping when they get near your planet, you get no warning.
The solution? Always leave at least one hostile wormhole with a warp gate. This actually works out well, defensively speaking, because then you know where the enemy waves will all come in. Of course, any way you cut it this situation is likely to be short-lived: as soon as you take another planet, you'll have a whole new batch of hostile wormholes to content with, anyway. But in the interim, it gives you a nice defensive position without blinding you to incoming waves.