The gender of Frisk, the protagonist of Undertale, is not specified in the game and is left up to the player to decide. Frisk is referred to as "they" or "dude" by other characters in the game. Some fans interpret Frisk as male, while others interpret them as female or non-binary. However, there is no official confirmation of Frisks gender from the games developer, Toby Fox. Therefore, Frisks gender is ultimately up to the interpretation of the player.