They're not actually that hard, but you generally need to exploit loopholes to beat them:
- Don't build starbases or leave ships on planets (they automatically see and attack them)
- Make a fast ship (speed 13+), and fly it in circles around their homeworld, taking care to stay just out of the range of their attack ships. You can often get nearly their entire fleet to follow you, endlessly.
- Keep a defensive line of fast light ships to pick off their transports; their transports almost always move 10, but their combat ships move 6, so they don't escort their transports very well.
- If a DL combat ship does wander through your territory, just ignore it and keep your ships out of the way; Galciv doesn't allow planetary bombardment, so they can't hurt your planets without transports.
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