The screenshot I am starting here with is a picture of my empire in crusader Kings 2. The name of the Empire is Prydain, which I learned is the Welsh term for the British Isles. As you can see by this map of Europe, it is a very different place than in our reality, but I think I have learned more about the middle ages from this game than my studies. It is an exercise in counterfactuals, but under the hood it is employing powerful simulations that not only teach you about the dynamics of the period, but really make you make the decisions one would make with these factors.
CK 2 is a dynamic simulation of the politics of the middle ages. It's game map simulates all of Europe and the Middle-east, with plenty of northern and sub-saharan Africa, the Indian subcontinent, and the caucuses. You can play as a ruler from five different government types, many religions, and countless cultures, and see just how patters of conquest, settlement, and ruler-ship shape the complex dynamics of the modern world.
You can start at any day from the 8th century, and the game ends in 1444. You can play as famous rulers such as Charlemagne, or William the Conqueror, or as a nameless Icelandic count. Through manipulating the mechanics of the game, which reflect real trends and decisions of the age, and grow and conquer. There is no real win condition, and the way to lose is to have your branch of your dynasty die without heirs.
Every single rulership title (and also everybody's court) is populated by characters. These have various traits and ambitions absed on genes, education, or just chance. I'm not writing a manual, but with a picture of a character page you might be able to see just how vaired and complex every character is.
This guy is an emperor, but his empire consists of kings in vassalage under him, dukes under them, counts under them, and barons, mayors, and clergy under them. All with their own character and their own AI. It teaches the valuable thing about ruling in Feudal lands. Just how unstable everything is, and how most of the work is just keeping those under you in line.
Alliances and war cannot happen arbitrarily. Depending on culture,.religion, and claim, wars need a just cause in order to start, even if you fabricated it. In order to call in allies, the rulers will decide for themselves if they want to help you. And of course you must call upon levies from your vassals, and the amount they send is based on how much they like you. How do you manage that? There are various paths such as bribes, festivals, feasts, honorary titles, or other favours.
Marriages build alliances, can spread claims and genetic traits to children, and effect the efficiency of the state. You have to choose them carefully just as you had to in the middle ages.
Maintaining a stable hierarchy is part of the game. This means balancing different succession laws, and levels of centralization amongst ambitious and plotting vassals. Or content and happy ones, depending on who you put in power.
One of the biggest ways to differentiate playstyles is religion. Catholics, Orthodox, Sunni, Shia, Ibadi, Buddhist, Hindu, Norse, Zunist, Zoroastrian, so many religions leave powerful marks on how the game works.
Where I think this game works best as not just entertainment, but education is in the simulation aspect. It covers all the trends and strains of the middle ages, and then uses those as the core mechanics of the game, leading to many many different worlds that are actually oddly believable.
Some lessons I learned:
Crusades are almost guaranteed to be disasters
Stopping the Muslims in Iberia was an extremely hard thing to do
Almost every king has major family issues
Many pagan cultures grew quickly, but were fundamentally fragile.
I feel that these are more educational to understanding the period than memorizing battles, dates, and events. They open up interesting unheard chapters of history to those that might not have seen the value before playing it.
Paradox not only develops this title, although they still continue to update it with the game's 9th expansion releasing in July. Theior engine has been adapted with different mechanics, pulls, and forces to different periods of history. Here is a quick list:
Europa Universalis (1441 - 1821): This covers the era of colonization, and empire building. Be the brutal conquistadores, or weather the European attempts at colonization as the Aztecs. Lots of options in a truly global context.
Victoria (1835 - 1935): This covers the last eras of colonization, industrial revolutions, and great wars. This is the oldest of the ones I am mentioning here. It came out in 2008 and will likely see a new version in the next 5 years.
Hearts of Iron(1936 - 1948): Running in increments of hours instead of days, this game simulates the second world War. This includes the fight for technology, supply lines, armies, and alliance cooperation. I have not played the older one much, but the new one is expected in 2016.
These simulations like all models of history are very incomplete. Often several things need to be simplified in order to improve the ability to run (CK2 is very CPU intensive) and sometimes those decisions come out as problematic. For example, one complaint about Crusader Kings is that the laws of succession are a little too clean. They were not always followed perfectly, and the game can't accommodate it. Another one would be that people of equal rank Kings and kings or dukes and dukes cannot be vassals of each other. This mostly works out with history, except for that one time when the King of England was also a Duke in the French kingdom, basically setting the stage for the hundred years war. Not perfect, but what can you do? Given the amount it provides, I think it certainly holds more value than you lose with these inaccuracies.