Civilization 5 addon Gods and Kings add and improves miscellaneous features. Civ5:G&K improves the game balancing. Civ5:G&K accelerates the turns with an improved combat processing. Civ5G&K tweaks many civilization properties, especially those of the Songhai. Civ5G&K adds also new music and new background images for the main menu and the loading menu. The general improvements like balancing, artificial intelligence, combat system etc. are also announced for a future Civilization 5 patch. Civ5 Gods and Kings improves the Artificial Intelligence Civ5:G&K improves the AI on all levels so that it is noticeable stronger. Civ5:G&K makes the AI more concentrate in the end game so that it focuses more and is faster on building the spaceship to Alpha Centauri. Civ5:G&K gives the AI the ability to consider how much it is willing to do a nuclear first strike. ...

Gods and Kings emphasizes quests to gain influence in city states Gods and Kings adds to Civilization 5 new types of city states, and rebalances the city states. City states cannot just be bribed with gold to gain influence there. To gain influence in city states, it is more important in Gods and Kings to complete quests for the city states. City states can offer in Gods and Kings up to three quests. The available quests and their type can be viewed in the diplomacy overview. The quests are divided into two types: Global quests and religion or civilization specific quests. Global quests can be completed by any player on the map. Global quests can directly turn a city state into an ally. Global quests examples are:...

Gods and Kings adds 3 new scenarios to Civilization 5. The scenario is in particular interesting: A steam punk scenario that takes you into an alternative reality. But let's talk about the scenarios in their order.

Fall of Rome

Play as either Eastern Rome or Western Rome trying to fend off the barbarians OR as one of the barbarians themselves. (Webhallen, Official) Both Eastern and Western Rome have to pick Social Politics, that have negative effects. This is supposed to reflect the political decay and decadence. The Social Politics make also the Barbarians stronger to make the struggle for survival harder.

Into the Renaissance

Grow your medieval kingdom into one of the great nations of Renaissance Europe, fending off outside invasions from Mongols and Ottoman Turks and fighting the religious wars of the Crusades and Reformation! (Webhallen, Official) This scenario mainly focuses on spreading religion under leadership of a major European empire.

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Gods and Kings adds one new era to Civilization 5

Gods and Kings adds one new era to Civilization 5. The new era has so far no known name, but it is placed between World War I and World War II, and tentatively called the Great War era. Ed Beach: "...there is no so called Great War era, we only used this terminology to describe a class of units. We have, however, added a new era to the tech tree that should help us to extend the post-gunpowder world a little bit further."

With the new era we get new units, especially WWI, and the Infantry has been split into a WWI and WWII.

Gods and Kings adds 5 new technologies to Civilization 5

Gods and Kings adds 5 new technologies to Civilization 5. Here is the list:

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Gods and Kings adds 52 new achievements to Civilization 5. Here is the list of the achievements, directly grabbed from the official Civ5:G&K website:...

The changes to diplomacy Gods and Kings adds to Civilization 5 diplomacy, embassies, religion, espionage, ideological blocks, and addresses some imbalances. Civ5:G&K addresses imbalances with the AI (artificial intelligence, computer player). The AI does not dislike you anymore if you are just "trying to win the game the same way as" the AI itself. The AI does not mind so much anymore if you settling closely when the empire borders are already clear and settling is just about closing gaps. Whether the AI considers you a warmonger depends now whether you have started the war or not, this seems to be related to conquering cities and city states. Additionally, the AI forgets things more easily so that wars do not tend to run forever. Other balancing changes concern the research agreement, it now requires Education instead of Philosophy and both civilizations must be now friends. Gods and Kings brings embassies to Civilization 5 diplomacy. Embassies are available from the Classical Age and reveal the capital of the other civilization. Embassies are required for agreements like Defensive Pact and Open Borders. Embassies also allow access to the intrigue menu that is part of espionage. Espionage is an important factor in the late game when religion ceases to be important. ...