War posts a A few tips on defense.

1) Always build your military/forts/towers just behind your cities, not in front.

2) Build watch towers by shooty buildings (towers/forts)

3) Spies can really save you in defence, taking the siege away.

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Read 'em all.

UPDATE: Beware of his urging to use decays at all times. Decoys count against unit count for purposes of ramping costs. So unless you are 1) already at ramping cap, or 2) need the decoys urgently, be careful about abusing this general's ability.
posted by Tim at 8:46 PM