Vault Boy is the iconic mascot of the Fallout video game franchise, representing the Vault-Tec Corporation. While often mistaken for 'Fallout Boy', he serves as the face of the series' dark humor and mid-century aesthetic. The meme typically features his signature thumbs up pose, which fans often associate with the 'rule of thumb' for measuring nuclear blast distances. In internet culture, the Vault Boy template is used to express optimistic approval in the face of catastrophic situations, general enthusiasm for gaming achievements, or ironic satisfaction with a questionable decision.