Choose exactly when to make major decisions that will shape the future of your country. Strive to Create Great Britain, Establish the Spanish Inquisition, or Institute the East Indian Company. Act rather than react, on both country and province level, with the new Decision System, including hundreds of different situational decisions.
Experience the new Mission System, where the player and AI alike will be given goals to achieve, providing endless replayability by guiding history along different tracks every time.
Rebels with a Cause: there are countless types of rebels, all with different goals, and different abilities. You may get colonial rebels overseas, striving for representation or independence, or you may see reactionary nobles rise up to put the serfs back where they belong. Crush the rebels by force, negotiate with them, or even worse; watch them enforce their demands on your country.
Religious tolerance now depends on the ideas and decisions you take, adding a new layer of strategy. As cardinals stay loyal longer, the power of the Papal Controller has grown, as he can now excommunicate rulers, and call crusades against infidels.