1x1x1x1, also styled 1x or The Adversary, is a fictional killer from Forsaken, a Roblox one-vs-all survival game where survivors repair generators while one killer hunts them. The character grew out of an urban legend from around 2007 about a fourth-dimensional being who hated three-dimensional existence. 1x1x1x1 became a permanent, purchasable killer on December 25, 2024.

They are known for long-range attacks, piercing projectiles, crowd control and an army of zombies revived from slain survivors. In the game's story, 1x1x1x1 is the physical form of Shedletsky's hatred, born when Shedletsky was forced to separate from it. Their