Just a couple of months ago, Civilization VI announced its first expansion, titled Rise and Fall. It promised to not only add new civilizations for players to choose, but also new systems that would have a drastic effect on how the game was played. Today, a new trailer dropped that goes into more detail about exactly what those systems will look like in action.

One of the biggest changes to the game is how the player progresses between eras. Traditionally, players would advance their civilization through each era systematically and based almost solely on scientific research progress. Now, at the start of each new era, players will make a dedication, a decision about their goals for their society in the upcoming years. If they succeed in those goals, they will usher in a Golden Age. Fail, and players will have to deal with the consequences of a Dark Age.

Certain specified moments of greatness will allow opportunities for civilizations to advance. Tasks like discovering a natural wonder, founding a new religion, or clearing an encroaching barbarian camp will earn era points that will help usher in a Golden Age.

A new loyalty mechanic means that rulers will have to pay close attention to how their citizens are feeling, or cities may begin to rebel. A successful rebellion means a city becomes its own free state. Though it can be brought back into the fold if loyalty is increased, it can also be wooed by other empires to join their ranks. The new system also includes Governors in various cities who can be promoted and unlock opportunities to increase loyalty and build unique tile improvements.

There are plenty of other updates coming, from enhanced alliances to emergency events. The trailer contains more details and gameplay previews. You can view the full video below.

Civilization VI: Rise and Fall comes out on February 8, and players would do well to remember that the game and its DLC are all available in this month’s Humble Bundle.