Summary
During single-player games ofCivilization 6, a player will meet other civilizations also vying for the domination of the world that the AI will control. Some of these civilizations might be able to compete better than others due to various reasons, spanning from technological advantage to aggressiveness of their policies.
Due to these facts, players must always be on the constant edge to watch for any signs of incoming hostility from certain AI players. Not only that, in higher difficulties, it will also fundamentally change how a player plays their early game due to the advantages the AI civilizations have over the players.

7Tamar
Aggressive Attacks Via Religion And Military Units
Players with hopes of winning a Religious Victory,which is notoriously difficult, will need to be cautious if their neighbor is Tamar of Georgia. Her affinity for both having a strong fortified city and numerous faith generation makes her a formidable opponent, especially due to her particularly aggressive AI.
It would be ill-advised for a player to try going toe to toe against Tamar’s religion in aCivilization 6game, more so with her unique ability to generate faith out of killing units. A player will also need to be super cautious once Tamar is able to declare a Holy War casus belli due to differing religions.

6Lautaro
Great Hunter Of Civilizations With A Golden Age
Players will usually aim for a Golden Age to increase the advancement of their civilization and keep up the momentum of their lead. Moreover, having a Golden Age can also enable a player to expand rapidly via the overpowered Monumentality Golden Age, which enables them to purchaseSettlers and rapidly expand their border.
However, Lautaro of Mapuche can easily smell blood after seeing a civilization reach the Golden Age, since his unique ability enables him to gain an advantage against units from a civilization with Golden Age. Therefore, necessary caution is advised when getting a Golden Age with Lautaro nearby.

5Pedro II
Able To Maximize Rainforests For An Early Lead
Rainforests in the early game were quite beneficial due to their huge yield in both production and food, making a city able to grow rapidly through the eras. Pedro II of Brazil made it trickier by having a unique bonus tied to rainforests, with adjacency bonuses for every rainforest next to a district.
Pedro II’s unique personal ability also makes him quite formidable inacquiring Great Person rapidlythroughout the era, making it challenging for a player to aim to have a Great Person of their own choosing. Coupled with AI’s tendency to build districts, Pedro II is a formidable opponent to have.

4Peter
A Huge Obstacle In The Late Game
Both in the hands of a human player and AI, Peter of Russia continuously becomes a tough opponent to face due to his huge advantages over unusual terrain. Mother Russia’s unique ability enables him to benefit greatly from Tundra tiles, and when coupled withDance of the Aurora Pantheon, Peter can generate faith easily.
Moreover, after accumulating heavy advantages in the early game, his lead would be converted into a mid-game threat with the addition of Cossacks. These unique units would be able to conquer any lightly defended cities, and Peter could build them easily with faith purchases through the Grand Master’s Chapel.

3Jayavarman VII
A Love For Border Expansion Via Growth And Wars
In everyCivilization 6multiplayer game, Khmer players have always been a target due to their potential to snowball out of the early game into the next era with their massive food production toenable rapid growth of cities. Coupled with AI bonuses, Khmer can potentially be a very tough opponent to face.
Moreover, their tendency to be aggressive with both military units and religious conversion makes them dangerous in all stages of the game. Waiting to strike down Jayavarman VII until the mid-game could be a death sentence as he would be well-equipped with the fearsome Domrey.

2Hammurabi
Create An Oppressive Early Game For Everyone
In hindsight, Hammurabi is not a powerful AI opponent to face due to the AI’s inability to efficiently use theEureka system to break the game. However, even the AI will be able to achieve a quick advancement in technology in early games for certain technologies.
In turn, this will make the Barbarians quite difficult to address due to the units keeping up with the highest technology in the game. It will not be a rare sight to see Man-At-Arms barbarians almost as early as in the 50+ turns, making the early game hellish for everyone in the game.

1Genghis Khan
Be Wary Of Mass Keshig Rush In Medieval Era
Having a warmonger civilization as a neighbor can sometimes be a game-over scenario in higher difficulties, such as Immortal and Deity games. This problem will be intensified once the warmonger civilization is revealed to be Genghis Khan of Mongolia, as he will most likely be using hisunique modifier to gain combat strengthadvantage against other civilizations with his unique ability.
Moreover, his tendency to mass produce Keshig in the Medieval Era will prove a headache to even the veteran players ofCivilization 6, as the unique unit is quite mobile with the added boon of having a ranged attack. A player will need to quickly garrison their borders and fortify their cities once they find out that Genghis Khan is knocking around their territory.
