No DLC is required, but Mandate of Heaven is recommended.

General historical/balance changes

Absolutism now grants completely new bonuses (and a few penalties).

Administrative efficiency bonuses have been returned to tech.

Republics now treat all non-accepted cultures as if they were in the same culture group but not accepted. They also now have a base gain of +1.5 republican tradition (up from +1).

Constitutional monarchies and republics get new bonuses in the Age of Revolutions, including republican tradition/legitimacy, as well as a slightly increased income from all sources.

The Enlightenment institution: Can now only spawn in Europe Spreads much quicker through adjacent friendly provinces Spreads much slower if the nation trying to spread it (using universities/parliament) is outside of Europe, unless that nation is a player.

The "Napoleonic Warfare" ability from the Age of Revolutions now grants a +7 bonus from artillery vs. forts.

The Revolution is much easier to prevent now, allowing for greater player control over whether or not they want it to occur to them, and leaving room for the French to have their revolution.

Being the Revolution target now grants event more powerful bonuses.

Rebels teleport twice as fast now.

The end date is now 1836.

Formable/spawnable nations

Latin Empire, complete with its own ideas. Can only be formed directly by the Knights, Cyprus, Athens, or Naxos, but can be released as an independent state by anyone Catholic with cores on the area of Thrace.

North German Confederation, which, if formed, will dismantle the HRE.

A proto-Republic of China now can form in a disaster similar to the Revolution disaster which can occur if the Emperor of China embraces the Enlightenment and has a low mandate. The chances of it forming are increased if the Emperor is not in the Chinese culture group.

The Mongol Empire can be restored by anyone with the Altaic culture group and the provinces needed. It shares a new set of national ideas with the 1444 horde of Mongolia.

Belgium can now spawn due to an independence war in the late Age of Revolutions, or by a player with Flemish or Wallonian culture and the required provinces, granting its new set of national ideas.

Europe

An Italian Wars event chain is now implemented, and will usually result in a victory for Castille.

Charles V will become the heir of Spain at some point between 1485-1575, and will transfer the Low Countries from Austria to Spain upon succeeding to the Spanish throne if Austria holds provinces in the region.

Restoring the Pentarchy as any Orthodox nation will give every non-Coptic Christian nation an event to convert to Orthodox. If the nation with the event is Catholic, they will get a bunch of penalties if they refuse to convert. If they're Protestant or Reformed, they gain prestige by refusing. Almost every AI nation will accept (this may change in the future).

The Burgundian inheritance is now almost guaranteed.

AI Poland should now only appoint a local noble instead 1 percent of the time.

The Dutch Independence event is now almost guaranteed, and the nation fighting the Dutch is now considered the attacker, allowing for the Dutch to call in the allies they gain from the event that gives them some.

The French Revolution is now guaranteed to fire in 1789 if no other revolution occurs before then. Napoleon should spawn 99% of the time now, as well.

In the late Age of Revolutions, the Greeks and the Belgians can fight their independence wars.

The events for the independence of Greece, Belgium, and the Netherlands now allow for the player to recognize the independence of the nations without fighting any wars. They also allow for the player to switch to the spawned nation, if they choose to do so.

The rise and fall of Aq Qoyunlu is now railroaded, as well as the rise of the Mughal Empire

China

Increased mandate now grants much greater bonuses, but decreased mandate gives much greater penalties.

Having less than 10 mandate will increase national unrest by 10.

All nations with the Chinese culture group now have the "Unify China" casus belli along with the Emperor, just like before.

The "Unify China" and "Take Mandate of Heaven" have dramatically reduced warscore costs for provinces, allowing for China to be quickly unified if it collapses.

Any provinces in the Chinese superregion that are taken by either the Emperor of China or a nation with Chinese culture will immediately become a core of that nation.

The Shun dynasty will now make its ill-fated rise, giving an opportunity for the Manchus to rapidly conquer China (which will usually happen).

If the Empire of China is dismantled, it can now be restored by any non-republic with Eastern or Pagan religion and enough provinces in China.

Map Tweaks

No new provinces are added, nor will I ever add any (which means this mod will be compatible with any mods that don't change the map), but there are some changes to existing provinces:

The size of the province of Ceuta is now the historical size.

Venice now somewhat resembles the real-world Venice and not a weird box in the Adriatic.

Luxembourg has been cut down to its real-world size.

Prussia's map color is now Prussian blue.

More railroading of important nations during the Early Modern period

Improve the Italian Wars

Improve the balance of Absolutism

Add in more formable nations in general

Improve China in numerous ways

Add in the ability to form Revolutionary Coalitions against the revolution target

Partially scripted wars/events if the French Revolution happens

Nation dismantling events (ex. dissolution of the Commonwealth if it no longer exists)

Make more map tweaks

Add a semi-diplomatic method for uniting Germany if the HRE is dismantled in the Age of Revolutions

Optional colonial railroading for historical colonies.

Add in the Republic of Turkey, if the Ottoman Empire becomes a republic.

Different election events for different republics.

And a bunch of other stuff...

Currently empty.

The mod is not ironman compatible, of course.