Social casino gaming, which simulates gambling games on social platforms, has become increasingly popular and is rapidly merging with the gambling industry. Advertisements for social casino games, however, are not bound by the same regulations as real money gambling, despite their similarities. We performed a content analysis of a sample of 115 unique social casino gaming advertisements captured by young adults during their regular Internet use. The results showed that the advertisement imagery typically featured images likely to appeal to young adults, such as bright colors, character images of young adults, cartoon animal characters, gambling and sporting activities, references to popular culture, and references to Las Vegas. Latent and manifest message themes included glamorization of gambling, winning, normalization of gambling, play for free, and a general encouragement to play. Notably, nearly 90 percent of the advertisements contained no responsible or problem gambling language, despite the gambling-like content. As young people are receptive of messages that encourage gambling, we recommend that gaming companies recognize the potential harms of advertisements and embrace corporate social responsibility standards. This includes adding warning messages to advertisements for gambling-themed games and ensuring that marketing messages do not encourage excessive gambling.