The game includes different bookmarked starting dates called "scenarios", with the world state, borders and events reflecting their historical equivalents for each. The earliest scenarios begin on 11 November 1444, one day after the
Christian defeat at Varna, while the latest scenario begins on 21 September 1792, the
end of the French monarchy. The player can also choose any day within the games time span as a starting date. The game itself is an interactive map of
Earth divided into the
provinces that compose nations. Each of these provinces contribute to their country either positively or negatively, as provinces can both provide resources to a nation and serve as a point of unrest and rebellion. At the beginning of the game many provinces are considered "uncolonized" and are meant to represent possible land colonizable by other nations. The gameplay requires the player to lead a nation by finding a balance of
military,
diplomacy, and
economy. The player does so through their choices as sovereign of their nation, and the spending of resources available to them: prestige, power projection, stability, gold (ducats), manpower, legitimacy for
monarchies, republican tradition for
republics, devotion for
theocracies, horde unity for
steppe nomads, meritocracy for
celestial empires, and monarch power (administrative, diplomatic, and military). Players can choose to conquer the world by military might, become a colonial superpower, establish trade dominance, etc. as one of over 500 different nations. The game is a
sandbox environment; there is no strict
win condition for players. A player's game ends when the player's nation is annexed (removed from the map) or when the in-game date reaches 3 January 1821.
Diplomacy is a large aspect of the game, as creating
alliances (or
vassal states and
tributaries), improving opinions, and preventing defensive coalitions are vital to a player's survival. Espionage can also be employed against enemy states to claim their territory or incite rebellion in their provinces, along with other dubious ends. Combat can be waged on both land and sea, during which the game attempts to simulate real-world factors such as morale, discipline, varying unit types with associated strengths and weaknesses, competency of leaders, terrain, and supply lines. Trade is also an important part of the game, where the world is divided into many trade nodes, and trade flows through each of the nodes and can be collected by merchants. Many major
religions, such as
Catholicism,
Orthodox Christianity,
Protestantism,
Sunni Islam, and
Shia Islam, are present in the game and can provide distinct bonuses to their practitioners. Players can employ missionaries to convert their provinces or can engage in policies of universal religious freedom. For example, the Catholic faith makes use of the
Papacy, which can allow a nation to have control over the Pope or to use its influence for other rewards. Native American and Aboriginal religions are also present in the game, most commonly utilizing a system of selecting a bonus for the lifetime of the present monarch. Furthermore, many of the world's institutions, from
feudalism to
industrialization, are also present in the game. Institutions normally appear around a certain year, and begin spreading through provinces. The rate of institution spread and where the institution spawns are malleable to player actions. Once reaching requirements, usually consisting of a ducat cost and a certain amount of institutions present in the player's provinces, the player can embrace the institution. Foregoing embracing an institution for too long increases a nation's technology cost; embracing an institution gives an institution-specific nation bonus, as well as purging any technological maluses that the lack of institution may have incurred. Technological advancements are invested in over time, and require the expense of monarch points. They provide benefits to the nation as detailed below: • Administrative technology unlocks advancements such as increased productivity, new forms of government, new buildings, and the national idea system. • Diplomatic technology unlocks advancements such as naval units, improvements in trade, new buildings, and improved colonial expansion. • Military technology unlocks advancements such as new types of land units, improved unit morale, combat tactics, and new buildings. Gameplay is influenced by random events that arise periodically for the player. These events can be either helpful or harmful. Some of these random events are driven by an individual country's history, while some can apply to any country and serve generally to enhance the "flavor" of the game. Some events are also motivated by various institutions that occur throughout the history of the game, such as the Industrial Revolution. Players can choose to play single-player mode versus the
AI, or multiplayer over a
LAN or the Internet against a mix of human and AI opponents. Single-player also has the option of "Ironman" mode, which locks several settings such as difficulty, and removes the control of saving the game from the player. This means that any mistakes are irreversible. It is, however, the only way to receive any of the game's many
achievements. ==Development==