What's the use of five civilized city-states? Explain in detail the importance of the five civilized city-states.

The "polis" in Civilization 5 mainly has the following functions:

1, polis represents many small civilizations in the world. A polis is a country composed of a central city. They can't form immigrants, so they can't build new cities (they can only expand the boundaries of cities), but city-states can acquire enemy cities through military conquest.

2. offer help. If a player is close to a city-state, it will provide food, culture and even military power for the player's main city.

3. Expand the field. If a player attacks a city-state, he will get a new city to expand his empire, but this may lead other city-states to declare war on the player, so think twice before you do.

Extended data

There are five types of polis, including three types at first: cultural type, military type and marine type, and then two types of expansion were added: commercial type and religious type.

1. Cultural polis gives players a certain number of cultural points in each round.

2. Military polis regularly presents ground military units to the nearest player city.

3. This maritime city-state will provide food for all the cities of the players.

4. The commercial city-state enhances the happiness value of the civilization chosen by the players and provides a luxury resource (such as porcelain).

5. Religious city-states give players a certain number of belief points each round, and the first civilization they encounter can also get belief points rewards.