Random build challenges became a trend among Sims YouTubers in April 2020 following Vixella's The Sims 4 but every room is a different pack. This mode of gameplay incorporates computerized randomizers to make building decisions and represent the challenges and risks associated with aleatory invention (Holmes, 2016, Lauer, 2016, Leadon, 2011, Vitanza, 2000). However, these challenges and risks emerge partly from material agency. To explore this phenomenon, I herein use Jane Bennett's (2010) vital materiality as a theoretical lens to examine random build challenges. Central to Bennett's theory is vitality, an agentive quality of both human and nonhuman materials that yields an effect—or in some cases affect—on other materials involved. Through examining three examples from popular Sims 4 YouTubers, Plumbella's random pack build; Lilsimsie's random townie build; and finally LaurenZSide's random meme build, this article demonstrates how player, game, and randomizer vitalities collaborate, compete, and co-exist. In addition to the videos serving as examples of aleatory building processes, random build challenges pose opportunities for experienced composers to implement new approaches in response to aleatory elements that can be adapted to other composing settings.