Sentry/Guard Towers can be defeated by Catapults or Ballistas
(Siege), Phalanxes.
Catapults and Ballistas can be defeated by Villagers, Elephants,
Phalanxes.
Ships can be defeated by Catapults, Guard Towers, Fast Fire Ships.
Phalanxes can be defeated by Elephants.
Elephants can be defeated by Ships, a group of Phalanxes.
Archers can be defeated by Elephants, Sentry/Guard Towers.
Chariots can be defeated by Elephants, Sentry/Guard Towers.
Scouts can be defeated by anything except Villagers.
Villagers can be defeated by anything including villagers.
Strategy: Civilization: by Mewtwo150