Total War: Attila is [..] the ninth standalone game in the Total War series of video games.
The game begins in 395 AD, during the transition from Late Antiquity to the early Dark Ages. While the title character will be able to become the leader of the Huns, he is not yet in power at the start of the campaign.
The campaign map for Total War: Attila spans from Bactria to Lusitania and from Caledonia to Garamantia in the Sahara. Provinces are groupings of three regions, and each region within a province can be conquered separately. The number of cities and regions is different from Total War: Rome II, but the size of the map is similar. The map of Total War: Attila further extends into modern day Russia in lieu of the eastern provinces of the Hindu Kush found in Total War: Rome II, shifting the player's attention to the nomadic Huns. The largest settlement in a province is designated as the province capital. These province capitals have more building slots than the other settlements and are also walled at the start of the game, though in a change from Rome II the small settlements can eventually be upgraded to have walls.
The game focuses on the latter stages of the Roman Empire after its split in 395 A.D. upon the death of Emperor Theodosius I with his sons each ruling a half: Honorius in the West, and Arcadius in the east. Since the days of Diocletian it has become a custom to divide Rome as the pressures to govern the empire have become too much for a single emperor to handle. With the split of the empire both sides face multiple threats on all sides, including internal instability undermining each of the young emperors control as part of the long term repercussions of the Third-Century Crisis. When the game begins, playing as the Western Roman Empire gamers will face waves of hordes entering their borders as the arrival of the Huns in the east have caused them to flee in search for new homes. Since the death of Emperor Valentinian I and the division of the empire, the weaknesses in the West have rapidly begun to show and edge the empire closer to ruin. With depleted funds from centuries of internal mismanagement, the West is unable to muster an effective army to combat the invaders. The Eastern Roman Empire, with its new capital in Constantinople as the gateway for trade between Europe and Asia along with administrative reforms have turned it into an economic powerhouse in the game. Yet the Eastern Romans face an initial threat from the Visigoths hovering in Greece, able to even make a direct assault on Constantinople itself, and remain wary of the Sassanid threat in the east. If chosen to play either of the Roman empires, gamers will be tasked with saving and preserving the once-great empire, and if possible unite Rome under a single emperor.
As "Total War: Attila" embraces an era of great change with the peoples of Europe migrating across the campaign map, Attila adds a new dimension in the form of a faction's religious conversion in the game that brings an array of unique benefits across the player's empire depending on the religion that they choose to favour. The presence of a faction's state religion offers bonuses, including provincial edicts assigned, temple buildings, churches, and even character traits. These factors all play an important role in how dominant the player's religion is over a province. If a province has a population with several religions it can have a negative affect on public order and thus lead to revolts. Factions also suffer or gain religious penalties when engaging in diplomacy with each other depending on their chosen religious affinity. Should the player choose to convert to a new religion, their faction's overall population must have at least 35% of that religion to convert. To find which religion is dominant in a region the campaign map may be searched using the religion filter provided. For players who choose Christianity as their state religion, the five cities of Rome, Constantinople, Aelia Capitolina, Antioch, and Alexandria that formed part of the Pentarchy have the exclusive option for their churches to be upgraded to "Holy See" status, which comes with major bonuses. The game includes a total of 13 religions available throughout the campaign map, although the effects of minor religions are not fully understood.
Based on historical accounts, a mini Ice Age in this period plays a part for the peoples of Northern Europe to move to the more fertile south as the winter cold moves further down and engulfs Europe in longer winters as the game progresses. As an added new feature included in Attila, the Fertility of a region plays a crucial part when settling in a region if playing as a migrating horde or creating important buildings that deliver food throughout your empire. The campaign map is divided on various fertility levels that are color-coded and labeled; from highest-lowest: Rich, Good, Average, Poor, Meagre, Infertile. The greater the fertility level, the greater the amount of food can be cultivated with the appropriate buildings. However, the amount of food harvested is affected by a number of various external and internal factors. These include: building consumption costs, razed areas within your controlled province, provincial edicts, character traits, foreign armies raiding within your borders.
The game features 56 factions, 40 of which are unplayable. each with their own unit roster and agenda. Ten factions are playable in the game at launch, with others added via downloadable content (DLC) packs.
* The Huns
* Eastern Roman Empire
* Western Roman Empire
* Sassanid Empire
Source: Wikipedia, "Total War: Attila", available under the CC-BY-SA License.