Civilization V new features likes policies, city-states and non-stacked units require new strategies to be developed.
Here is a list of strategies to succeed in the game:
- Stay ahead in science. Research Writing early and build a library and the National College wonder while you have only one city. To build the National College each city needs to have a library so it is better to build it early.
- Focus on Gold. Gold will increase research and will allow you to provide gold gifts to city-states.
- Be allied with city-states. They can provide you with units, culture, gold, resources and research. It can be expensive so the Patronage policies are a good idea. If you are playing a game with diplomatic victory enabled, city-states will help you succeed.
- Eliminate other players early. Specially if they are militaristic they’ll hunt you sooner or later. Use archers and warriors. Attack with all units at the same time on the same city. Don’t divide your army unless you have enough units.
- Increase your culture as much as possible.
- Increase the generation of great people as much as possible, for example building the Garden city improvement. Great scientist can provide you with free technology and Great engineers can speed up the construction of wonders.