The Player is a co-protagonist of OFF, arguably serving as the central protagonist of the entire game. The Player's name and gender is determinant. They are tasked with guiding a being known as the Batter to accomplish his sacred mission to purify the world of OFF. Some characters in the game, notably Zacharie, the Judge, and the Batter himself, are explicitly aware of the Player's existence and will address them directly. The question of whether or not other characters know about the Player is deliberately ambiguous, although statements by the Queen in particular appear to hint at them knowing of their presence.
- The Player is referred to as the Batter's "puppeteer" by the Judge.
- The extent to which the Player is an entity within the game itself is somewhat ambiguous in that the Judge seems to indicate that the Player dies should the Batter, when being controlled by the Player, dies. This may, however, just be empty bluster and threats by the Judge.
- If the Player is identified as female, then she will be one of the only three characters of the game (Sugar, the Queen, and herself) to not be either male or genderless.
- The exact relationship between the Batter and the Player changes dramatically should the Player choose to abandon the Batter in the Room. Typically, the latter directs the former's movements while the former is generally passive. After being abandoned, the Batter retains his sense of purpose, yet the Player has the ability to fight on the side of the Judge, abandoning the mission assigned in the beginning of the game.