Game rule

Game rules are configuration choices available when starting a new game that can slightly alter some mechanics. Many such option will disable Achievements. Game rules can be saved as presets.

Difficulty

The difficulty setting can grant players the following bonuses:

Difficulty	Hostile Scheme Resistance	Fertility	Short Reign Duration	Tyranny Gain	Stress Gain	Knight Survival	Disease Chance	Health Boost	Faction Formation	Vassal Opinion	Liege Opinion	Achievements
Very Easy	+30	+20%	-50%	-75%	-50%	+75%	-75%	Moderate	Significantly Slower	+25	+50
Easy	+15	+10%	-25%	-25%	-25%	+66%	-15%	Small	Slightly Slower	0	0
Normal	0	0	0	0	0	0	0	None	Regular	0	0

Gameplay options

The gameplay options can change the game to be less historical.

Rule	Setting	Effects	Achievements
Exclave Independence	Off	Rulers can have disconnected land anywhere in the world
	Limited (AI Only)	AI Rulers at peace will lose disconnected land on succession unless it's part of their de jure territory or is connected to the capital by one county or a naval path
	Significant (AI Only)	AI Rulers at peace will lose disconnected land on succession unless it's part of their de jure territory or is connected to the capital by a naval path
	Total (AI Only)	AI Rulers at peace will lose disconnected land on succession unless it's connected to the capital by a naval path
	Limited	Rulers at peace will lose disconnected land on succession unless it's part of their de jure territory or is connected to the capital by one county or a naval path
	Significant	Rulers at peace will lose disconnected land on succession unless it's part of their de jure territory or is connected to the capital by a naval path
	Total	Rulers at peace will lose disconnected land on succession unless it's connected to the capital by a naval path
Multiplayer: Murder Schemes	Default	Players can use Hostile Schemes against other players and their families
	No Players	Players cannot use Hostile Schemes against other players but can against their families
	No Player Families	Players cannot use Hostile Schemes against other players or their families
Minor Diseases	Default	Minor diseases appear as per normal
	Fewer	Minor diseases appear 30% less often
Matrilineal Marriages	Default	AI characters will arrange matrilineal marriages if they belong to the player's close family, a Reputable Dynasty, an Equal realm, or are strong rulers Female Dominated realms default to Matrilineal
	Default (no Player exception)	AI characters will arrange matrilineal marriages if they belong to a Reputable Dynasty, an Equal realm, or are strong rulers Female Dominated realms default to Matrilineal
	Always	AI characters will arrange matrilineal marriages for all female Dynasty members unless target belongs to a Reputable Dynasty, an Equal realm, or are strong rulers
	Female Dominated & Equal	AI characters will arrange matrilineal marriages if part of a Female Dominated or Equal realm unless target belongs to a Reputable Dynasty or are strong rulers
	Never	AI characters will never arrange matrilineal marriages unless part of a Female Dominated realm
Gender Equality	Default	All faiths start with their historical views on gender, clerical gender, male adultery and female adultery doctrines All realms start with their historical gender succession law
	Equal	All faiths start with the Equal views on gender doctrine and Either clerical gender doctrine All faiths start with male adultery and female adultery doctrines at the same level (the lesser one) All realms start with the Equal gender succession law
	Inverted	All faiths start with their historical views on gender, clerical gender, male adultery and female adultery doctrines inverted All realms start with their historical gender succession law inverted
Regional Heresies	Strict	Heresies are 200 times more likely to be historical if they happen in certain regions
	Default	Heresies are 5 times more likely to be historical if they happen in certain regions
	Relaxed	Heresies are random no matter where they happen
Mongol Invasion	Default	An AI character will use the Become Greatest of Khans decision between the years 1180 and 1250 if the player doesn't do it before
	Never	Only player characters can use the Become Greatest of Khans decision
	Random	An AI character can use the Become Greatest of Khans decision at any point if the player doesn't do it before
Casus Belli Costs	Default	Casus Bellis cost resources
	No Costs	Casus Bellis do not cost resources
Culture Conversion Speed	Significantly Slower	The Promote Culture councilor task makes progress 4 times slower
	Slower	The Promote Culture councilor task makes progress 2 times slower
	Default	The Promote Culture councilor task makes progress as per normal
	Faster	The Promote Culture councilor task makes progress 2 times faster
	Significantly Faster	The Promote Culture councilor task makes progress 4 times faster
Faith Conversion Speed	Significantly Slower	The Convert Faith in County councilor task makes progress 4 times slower
	Slower	The Convert Faith in County councilor task makes progress 2 times slower
	Default	The Convert Faith in County councilor task makes progress as per normal
	Faster	The Convert Faith in County councilor task makes progress 2 times faster
	Significantly Faster	The Convert Faith in County councilor task makes progress 4 times faster
Diplomatic Range	Restricted	Diplomatic Range is reduced by 25%
	Default	Diplomatic Range remains unchanged
	Unrestricted	Characters can interact no matter the distance
End Date	1453	The game will end in 1453
	No End Date	The game will never end
De Jure Requirement	On	Every 5 years titles with de jure land will be destroyed if their holder controls none of their de jure land
	On (Limited)	Every 5 years titles with de jure land will be destroyed if their holder controls none of their de jure land unless it's a player's primary title
	Off	Titles with de jure land can only be destroyed manually
Custom Kingdoms	On	The Found a New Kingdom and Found a New Empire decisions are available
	Off	The Found a New Kingdom and Found a New Empire decisions are not available
Generate Families	On	Landed characters with no recorded family will start with a spouse, a valid heir, a second child if the mother is over 25 and a third child if the other is over 33
	On (AI Only)	Landed AI characters with no recorded family will start with a spouse, a valid heir, a second child if the mother is over 25 and a third child if the mother is over 33
	Off	Landed characters with no recorded family will not start with any family
Same-Sex Relations	Default	All faiths start with their historical same-sex relations doctrine
	Accepted	All faiths start with the Accepted same-sex relations doctrine
Sexuality Distribution	Default	Characters have a 89% chance to be heterosexual, 5% chance to be homosexual, 5% chance to be bisexual and 1% chance to be asexual
	Bisexuality	Characters have a 89% chance to be bisexual, 5% chance to be homosexual, 5% chance to be heterosexual and 1% chance to be asexual
	Homosexuality	Characters have a 89% chance to be homosexual, 5% chance to be heterosexual, 5% chance to be bisexual and 1% chance to be asexual
	Asexuality	Characters have a 89% chance to be asexual, 3.6% chance to be homosexual, 3.6% chance to be bisexual and 3.6% chance to be heterosexual
	Equal	Characters have equal chances to be heterosexual, homosexual, bisexual and asexual
Faith Acceptance	Default	All faiths start with their historical views on other faiths
	Full	All faiths start with the Full Tolerance special doctrine
Randomized Faiths	Off	All characters and counties start with their historical faith
	On	All characters and counties start with a random faith
Random Ruler Placement	Off	All rulers have start with their real historical titles
	On	All rulers have start with random historical titles
	On (Conversion)	All rulers have start with random historical titles and convert to the faith of their primary title's capital
Hungarian Migration	Immediate	The Mogyër Confederation starts having used the Prepare to Cross the Carpathians decision and in a war against the Kingdom of Bulgaria using the Migrate to Pannonia casus belli
	Historical	An AI character will use the Prepare to Cross the Carpathians decision between the years 890 and 910 if the player doesn't do it before
	Random	An AI character will use the Prepare to Cross the Carpathians decision between the years 872 and 910 if the player doesn't do it before
	Player-Only	Only player characters can use the Prepare to Cross the Carpathian decision
Scandinavian Adventurers	Off	Scandinavian adventurers will never try to target Russia or the North Sea
	Rare	Scandinavian adventurers will try to target Russia and the North Sea every 15 years
	Occasional	Scandinavian adventurers will try to target Russia and the North Sea every 10 years
	Frequent	Scandinavian adventurers will try to target Russia and the North Sea every 5 years
	Apocalyptic	Scandinavian adventurers will try to target Russia and the North Sea every year and do not require specific traits to launch Varangian Adventures

Ironman

Ironman is a special game rule that disables character switching and manual saving. The game is saved automatically once every 6 months as well as when exiting the game. Achievements can only be obtained in Ironman mode. In Ironman mode, the game over screen only has the option to exit to the main menu.