Orders are a resource used to issue commands across your nation. Instead of moving every unit every turn, as is traditional in 4X games, each unit can be moved as many times as desired, until the player runs out of Orders. There are many other ways to spend this resource: Combat, Construction, Events, Diplomacy, and so on.
Each ruler must prove that they are worthy of the throne. As you accomplish Ambitions, finish Wonders, and gain renown (as "the Wise" or "the Avenger" or "the Peacemaker"), your Legitimacy increases, granting additional Orders each year and improving your standing with the people.
Every turn in Old World represents a year, and the rulers are mortals who won't last forever. They will need to get married and produce an heir to continue their line. When a ruler dies, the heir who takes the throne chooses a new Ambition to make a new name for him/herself.
Old World has a powerful and deep dynamic event system that generates a procedural story for your nation based on your decisions, your accomplishments, and your characters. The game has over 1,000 unique events, many of which are inspired by historical events from the period. These events give characters Memories, Traits, and Relationships, which can then trigger later events, so be careful what you choose.