Guerrilla Games’ upcoming Horizon Forbidden West has been rated by ESRB with a Teen rating and a description has also been given for it.
ESRB usually provides some details on why the game has received this rating, and in the case of Horizon Forbidden West, they mention Blood, Language, Use of Alcohol, and Violence as the reasons for this rating.
They dive deeper into the various descriptions by providing a general summary of the content as seen below.
This is an action-adventure game in which players assume the role of a hero (Aloy) traveling to discover the source of a mysterious signal. From a third-person perspective, players traverse post-apocalyptic environments/landscapes, complete quests, interact with characters, and engage in combat against enemy tribes and robotic creatures. Players use slingshots, bows, javelins, and spears to kill enemies in frenetic combat. Puffs of blood are depicted as human enemies are hit; blood stains also appear underneath bodies in some environments. Players can also perform stealth attacks (e.g., spear impalement) to eliminate enemies discreetly. Cutscenes depict additional acts of violence: a character impaled by swords or spears; a character crushed to death by a statue. The game depicts drunk characters stumbling around, and in one area stating, “I’m inebriated”; one cutscene depicts Aloy drinking beer from a mug; several background characters are seen drinking alcohol in taverns. The word “sh*t” is heard in the game.
Based on their summary, there doesn’t appear to be anything explicit in terms of content. It is a pretty standard affair for a game like Horizon Forbidden West, or its predecessor, Horizon Zero Dawn.