Diplmatic Feedback: There is now a new interface in the diplomacy view called 'Diplomatic Feedback'. Here you can set your attitude towards other nations, see what provinces they are interested in conquering and see their Trust towards you and the amount of Favors they owe. Favors are gained by being allies and helping each other in war, and can be used to raise Trust or to call them into your wars. You can also set provinces as being of interest to your nation, so that AI allies know to give them to you in peace deals.
Estates: Nearly all countries now have Estates, representing powerful groupings in the country such as the Nobility or the Priesthood. Estates have a loyalty and influence level, and can control territory, granting various benefits at the cost of local autonomy. A powerful estate will have significant effects on the country that are good or bad depending on whether they are loyal or not. Estates that grow extremely powerful will attempt to seize power in the country or break away to form their own nation.
Native Policies: You can now choose a policy for you handle the native population in colonies between Coexistance, Trading or Repression, with each giving a different benefit.
Threaten War: Adds a diplomatic option to let you demand a province that you have a claim or core on. If the demand is accepted, the province is yours, otherwise war ensues.
Force Migration: Added a new casus belli that lets you force a migratory neighbor to move to another province.
Concede Colonial Area: Added a new peace option available when you have a Colonial Nation to take all provinces owned by the enemy in that region.
Advanced Change Culture: Allows you to restore cultures or change to neighboring ones at reduced costs, rather than only the primary culture.
Declare Colonial War: When declaring war, you can now choose to make the war a Colonial War against overseas opponents. This disables calling in your allies, but allows you to call in your protectorates. The enemy can still call their allies as normal.
Name Your Heir: You can now name your heirs, and a button is available to re-roll another random name.
Horde Unity: Horde Unity is a new mechanic that for hordes replaces legitimacy. It decreases at a steady rate and must be maintained via looting and razing provinces.
Raze: Hordes can now Raze non-core provinces that they own. Razing a province lowers its development permanently and gives the Horde monarch power relative to the amount of development razed.
Tengri: Tengri nations can now pick a Syncretic Faith from among the religions in their provinces and neighbours. Provinces of the Syncretic Faith are treated exactly as though they were Tengri, using Tolerance of the True Faith, and countries of that religion will view the Tengri nation as though they were their own faith. The national bonuses for being Tengri differs based on which Syncretic Faith is picked, with a different set for each religion.
Grant Province: Added a new subject interaction that lets you grant a province to a subject.
Grant Core/Claim: Added a new subject interaction that lets you grant one of your cores or claims to a subject.
Build Directly to Army/Navy: Clicking the "+" buttons in the Army Panel will build a unit, move it to and merge it with the selected unit.
Build in Subjects: It is now possible to recruit armies and build ships in your subjects' lands, as long as their Liberty Desire is below 50%.
Distribute Spoils: When signing peace, gold and prestige is now distributed between allies according to war participation, instead of all of it going to war leader.
Victory Cards: Countries at 300 development or more will now get Victory Cards every 100 years from 1450 and forward, that will grant 1000, 2000,3000 & finally 4000 points if they are held. A victory card requires you to own, control & core an entire area, and will be randomly picked from nearby areas of possible rivals.
Study Technology: New spy action that allows you to send a spy to a more technologically advanced country to study their technology, granting +1 monarch power per month in each category where they are ahead by at least 2 techs.
Agitate for Liberty added: New spy action that allows you to send a spy to raise the Liberty Desire of another nation's subject.
Added events for Tengri Syncretic Faiths.
Added events for the different Estates.
Transfer Occupation is now available to players with The Cossacks, even if they do not have Art of War.
Disabled Sell Province to subjects when Cossacks DLC is enabled since Grant Province is a more fleshed out alternative.
Naval exploration missions from El Dorado are initiated when you click on Terra Incognita (if corresponding exploration mission is possible).
Massive rework to Random New World from Conquest of Paradise, now uses a tile-based system with custom scenarios to create far more interesting and believable RNWs. There is an option to enable or disable 'fantasy' content for RNW such as being able to encounter highly advanced native american empires.
Exclaves will now use regional naming (such as 'Swedish West Africa' instead of just 'Sweden')
Nation forming decisions now use permanent claims that do not expire unless revoked through war.
Implemented a concept called Revanchism, which gives countries that lose a war a boost to income and manpower recovery after the war.
Reworked mercenaries: Instead of a pool that randomly refills, each country now has a mercenary support limit of 20 + 33% of force limits, and can recruit up to this number of mercenaries of any mix of types they want. Mercenaries can now also be included in Army Planner templates, and will automatically upgrad when you change your unit type.
Replaced the events that assign trade goods to provinces with a system of scripted weights, and made it possible to see what trade goods a province can get by hovering over the 'unknown' tradegood in province view or hovering over the province in tradegoods mapmode.
No longer possible to pass through a canal if you're at war with or embargoed by controller.
New map modes selection interface: 10 rather than 6 slots, and four separate group lists: Political, Dipomatic, Geographical and Economical for easier searching.
A map icon will now appear in a province if combat is predicted between one of your or an ally's armies and an enemy army.
Macro Builder got a face lift, with more information and sortable columns.
Country View (the interface you get when clicking your country shield) got a face lift, with more and better spaced information.
Army & Navy maintenance will now automatically be raised, and forts will be activated, when you enter into a war. This feature can be turned off in the military view.
Ironman games can now be played with mods and various Gameplay Options. Achievements, however, will only be gained if certain criteria are fulfilled.
When starting a new single player game, a dialog for selecting Ironman or Normal game is now shown. The dialog shows if/why Achievements cannot be gained.
Achievements can now be viewed in-game by clicking the Achievements button next to the Pause button.
Added "Continue Game" button that starts the game from the last locally saved single player game.
Added "Prevent Nation Ruining" multiplayer Option which blocks certain destructive actions by players that have lost a war as long as the truces after that war are in effect.
Added 25 new achievements, 5 of which work specifically with Custom Nations.
The remaining armies of a country annexed as a result of a peace treaty now become nationalist rebels.
Cultural unions are no longer tied to tags, but rather can be gained for its primary culture group by any country with Empire rank (in Common Sense) or at least 1000 development (without Common Sense).
Countries with incomes less than 20 ducats will no longer get level 2 advisors (except by event) and countries with incomes less than 50 ducats will no longer get level 3 advisors (except by event).
# Autonomy & Cores
Development levels over 30 no longer contribute to higher coring and culture conversion costs.
Refactored local autonomy to apply multiplicatively to manpower, tax and production rather than additively. This makes effects of LA more severe.
Reduced impact of local autonomy on recruit and ship building times.
# Buildings
University now allows you to build an extra building in the province, so that there is no need to tear it down after developing the province.
Increased base number of buildings per province from 1 to 2.
Removed build cost increase from tropical, arctic and arid (still has development cost penalties).
Arctic provinces now have 1 less building slot.
Farmlands now only has +1 building (down from +2) but is 5% cheaper to develop.
# Capital
There is now a -5% per 100 country development bonus to development cost in the capital province.
There is now an increased cost for moving your capital to a province with a lower development than your current capital, higher the more total development you have.
# Culture
You now get a relation hit with every country that has the primary culture of the culture you are culture converting.
Changing a province's culture is no longer blocked by primary tag of that culture existing (exported to defines, default 0).
# Diplomacy
Removed opinion penalty for Competing Great Power as it has little effect and is frequently nonsensical in the early game.
Increased opinion impacts of rivalry.
Monarchies that are allied to revolutionary target now still get the penalty for a Revolution.
Breaking an alliance now gives a truce for 5 years between the nations breaking it.
Removed the 'Has Casus Belli' opinion modifier and increased opinion effects of having cores and claims, as the former did not mesh well with Imperialism CB in late game.
There is now a +50 opinion bonus with a neighboring country if you both border a more advanced neighbor (advanced as in it fulfilling tech group requirement to protectorate you).
Signing an alliance now removes the rejected alliance modifier between the countries.
No longer possible to select peace treaties for allies that do not want them (ie, can no longer feed unwanted provinces to AI allies).
Improve Relations is now bidirectional. Your opinion of the target country will also be improved at half the speed, up to a maximum of +50.
# Disasters
The Castilian Civil War disaster is now a disaster exclusive to Castille (unifying Spain in time will allow you to avoid it).
The Janissary Decadence disaster will now only trigger 100 years after the Janissary modifier is acquired by the Ottomans.
# Economy
Protectorates, Colonial nations and Personal Union juniors no longer have a penalty to their development cost, only vassals and marches.
Provinces now take longer to start recovering from being looted.
Provinces that have hostile units still standing in them will no longer recover from being looted, even if they have run out of loot.
# Espionage
Fabricate claims will be four times slower for the remaining duration if discovered.
Local Spy Defense is no longer a factor, instead all spy factors are global.
# Exploration
Countries with their capital in a colonial region can now auto-discover provinces in colonial regions, since they can't use hunt for the seven cities.
Reduced frequency land exploration events not relating to the Seven Cities of Gold.
# Governments
Hordes now get 50% less aggressive expansion.
Iqta now gives +5% global tax modifier instead of +100% heir chance.
Tweaked the bonuses of tribal governments to be more balanced towards each other.
Free reinforcement for Nomads is now tied to the Steppe Horde government form instead of ideas.
Noble Republic is now a very unattractive form of government that requires a very high percentage of land grant to nobility and can only be changed out of with a decision.
Hordes no longer take a prestige loss for selling provinces, returning provinces and releasing vassals peacefully.
# HRE
Increased maximum number of Free Cities in the HRE to 8.
# Ideas & Policies
Hormuz 4th idea now also gives +1 diplomatic reputation.
Most national ideas that were -15% or more build cost are now -10% build cost.
Colonial Ideas now start with -10% development cost instead of -0.1 inflation.
No longer possible to pick Naval or Maritime ideas for Primitives.
Replaced Quantity: National Arsenal with "Mercenary Contracts", giving +50% possible mercenaries.
Buffed mighty Gotland's ideas.
Reduced the power of Colonial Ideas' 'Religious Outposts' from +3% missionary strength to +2% missionary strength.
Policy for Quantity + Expansion now increases land forcelimits instead of giving an extra colonist.
# Mercenaries
Mercenaries can now be hired overseas.
War taxes now increases possible mercenaries by 10%.
# Nation Designer
Nation Designer now allows Native Councils in South America.
Random Setup: Less tendency to create superstates.
Doubled the Distance at which you can pick provinces that are not connected to your capital in Nation Designer.
Ruler skill now costs less points in governments with term durations.
Changed maximum number of Custom Nations, Client States and Colonial Nations to 75 each.
# Power Projection
Eclipsed rival is now +10 power projection (up from +5).
Power Projection now gives a Prestige Bonus of up to +0.5.
Reduced the power projection loss for having provinces taken from you by a rival.
# Religion
Greatly reduced doom reduction from occupying provinces.
Reduced the penalties from too high or too low Karma.
Penalty for high Karma is now discipline, and low Karma diplomatic reputation.
Shinto no longer gives negative tolerance to heathens.
Karma is now gained relative to the province development sum rather than province count. KARMA_PER_RELEASED_PROVINCE and KARMA_PER_TAKEN_PROVINCE were decreased from 10 to 1 in accordance.
Centers of Reformation can now only appear in temperate provinces with 10 or more development.
# Revolts
Most rebels can now relocate.
'Recent Uprising' modifier is now -100 revolt risk instead of -20, so it should always prevent revolts.
Giving in to zealot rebels of your own religion will no longer increase missionary strength. Instead it will add a 10% tech malus for 10 years.
Zealot rebels of your own religion will no longer convert provinces they take. Instead the religious violence modifier will be added to such provinces.
# Subjects
Removed Horde restriction on Marches.
Increased liberty desire from relative power of subjects.
Having the same dynasty as a vassal or march will now reduce their liberty desire.
Increased the base income and forcelimits of subjects slightly.
There is now a -100 opinion modifier for having force vassalized or enforced a union upon a subject.
Subject Interaction "Start Colonial War" now renamed to "Start War in Colony" to avoid confusion with new Colonial War concept.
Can now do the Enforce Religion subject interaction on colonies as well.
# Technology
Hordes reforming their government now always get the Chinese technology group unless they have a Muslim faith.
Nomad Group unit type now have units at various tech levels throughout the game.
Spread out the military tactics a bit further.
Halved Trade Efficiency and Production Efficiency gained from technologies.
# Units & Forts
It is no longer possible to block a strait for an army whose war allies control both sides of that strait.
Forts that have been captured by the enemy will now have a ZOC and block movement for enemies of controller.
Forts now have ZOC over any country's provinces (but only flip your own) meaning they can block enemy movement through friendly & neutral land. Movement through a country's own provinces cannot be blocked if a fort from that country is protecting those provinces.
Provinces can now be in the ZOCs of multiple forts.
Moving through ZOCs should now result in fewer unnecessarily long paths..
# War
Only the Coalition and 'Crush the Revolution' CBs can now be used to start coalition wars.
It is once again possible to transfer occupation to any war ally.
Forcing countries to revoke cores and claims on a 3rd party will give that 3rd party a little relation boost with you.
Peace demands now cause stability hit when declined if the negotiating country has at least 50% War Score and the AI would have accepted the demand.
Armies that win battles will now gain a significant boost to morale, to prevent situations where an army is stack wiped due to winning a narrowly fought battle and then immediately being attacked. Amount of morale regained depends on the strength of the enemy army defeated relative to their own strength.
You can now only call allies to war if you know they'll accept, and after they have been called they will automatically accept without calculating acceptance again.
Prestige gain from peace concessions involving provinces are now reduced by Administrative Efficiency (as you can take much more).
You can now sign a peace that would result in going down to -999 DIP, this to prevent situations where you're unable to make a suitable peace (which has higher priority than other DIP expenses).