History VideoGame / CrusaderKingsII

** The plot mechanic introduced in the sequel means everyone is plotting against everyone. That includes heirs, wives and brothers-in-law all attempting to stab you in the back simultaneously. If you're not the plotting type, your poor king can sometimes come across as the OnlySaneMan in a cast of psychopaths.
** The Sword of Islam expansion compounds on this by allowing up to four marriages for Muslim rulers (and punishing powerful rulers who have less than four marriages), all of which can produce legitimate children. This means a lot of plotting by wives trying to maneuver their own child into becoming heirs. Another notable addition is the decadence mechanic for Muslim dynasties, which can potentially cause problems for dynasties with unlanded males. The only things worse than plotting family members are plotting family members with land and armies...and family members who disgrace their family name by sitting around the palace drinking and chasing servant girls.
** The Old Gods expansion makes Zoroastrians playable - not only are sibling and parent-child marriages among them permitted, but are ''highly'' encouraged, netting a nice piety and vassal opinion boost if your ruler enters such a marriage. Unlike other faiths, children of incestuous Zoroastrian unions are five times less likely to have the "Inbred" trait, but five times more likely to have the "Lunatic" trait.

** Eventually, ''Holy Fury'' introduced this as a semi-hidden rule in random world generation. Said horses, cats, dogs, [[RunningGag polar bears]], hedgehogs, ducks, elephants, red pandas, and [[TheLastOfTheseIsNotLikeTheOthers dragons]] all become fully playable.

* WineIsClassy: One of the upgrades for the Patrician's palace in ''The Republic'' is the Wine Cellar, which [[ButLiquorIsQuicker provides a boost to your characters' fertility]].

-->''[[https://www.mobygames.com/images/promo/original/50939cbdeb554d5cb95cb587858f857b.jpg Tales of your misdeeds are told from Ireland to Cathay!]]''
-->''[[http://i.imgur.com/QALGAw4.jpg?1 Your low character is the subject of Greek plays!]]''

* ''Sons of Abraham'', released in November 2013, which focuses [[UsefulNotes/OrthodoxChristianity on]] {{UsefulNotes/Christianity}}, UsefulNotes/{{Islam}}, and {{UsefulNotes/Judaism}}, most notably adding the Jewish Khazar dynasty into the campaign map and including the College of Cardinals for papal elections, as well as finally making it possible to take your character on pilgrimage.

** ''Sword of Islam'' expands on this, giving Muslim characters the ability to observe Ramadan and go on pilgrimages to Mecca. Its main feature, the dynastic decadence system, is based on medieval Muslim historiography, especially as described in [[http://en.wikipedia.org/wiki/Muqaddimah the Muqaddimah]].

* BonusBoss: Invading China. There are steep requirements to fulfill before it is even possible[[note]]You must be an Empire-tier ruler, you must have 300 counties in your realm, you must border the eastern edge of the map, and China must not be destabilized[[/note]], the war itself is difficult (China sends larger doomstacks than even the Aztecs while all your counties have -75% replenishment), and losing the war means your primary title is destroyed. Essentially the only players who can attempt this are ones who have already conquered most of the world.

* IAmXSonOfY: Several cultures in the game use patronymic names. For example, the son of an Irishman will likely be <given name> mac <father's name>, while an Anglo-Saxon will be <given name> <father's name>sson. [[https://forum.paradoxplaza.com/forum/index.php?threads/the-obligatory-ck2-strange-screenshot-thread.585791/page-1096#post-22332505 This can have bizarre results when different cultures intermarry]], or if [[https://forum.paradoxplaza.com/forum/index.php?threads/the-obligatory-ck2-strange-screenshot-thread.585791/page-1095#post-22331952 applied to characters who get regnal names]].

* IHaveYouNowMyPretty: Followers of certain religions are able to force captured women to become their concubines.

* HumanResources: Under certain conditions, nomads can use the corpses of those killed during the razing of cities (not the looting, complete razing only) to fertilise their fields, giving them a significant population growth bonus. [[GameBreaker This can stack indefinitely.]] It may however have been patched out in later versions of the game, and it's not particularly clear what allows the option to be selected in the first place.

* BreadEggsBreadedEggs: There is nothing stopping the player from playing odd religion-government type combinations. Muslim merchant republics? No problem. Buddhist nomads? Possible. However, for them to be playable, you would require the corresponding expansions.

** Even ''Crusader Kings II'', it remains strictly enforced for merchant republics and nomads, which can only ever have strictly agnatic (male-only) succession for both the realm as a whole, and the heads of the houses/clans, no matter what their religion, laws, or bloodline would make possible for realms with other governments.