Civilization 6's Rise and Fall expansion introduced the concept of Ages to Firaxis' historical turn-based strategy. Based on the successes of a player's civilization during each Age of the game, they'll either enter a Dark, Normal, Golden, or Heroic Age in the next. The most beneficial of these is the Heroic Age, which offers Civilization 6 players a selection of powerful bonuses for their civilization, but is also the hardest to achieve.