Abstract
The paper aims to present a theoretical model of the interaction between an existing social norm against smoking near non-smokers and a governmental regulation supporting the norm. Drawing on the Brazilian anti-smoking regulation, where the government enforces the law against establishments that allow their clients to smoke within their dependencies, we propose an evolutionary game model to explain: how the interaction of a smoker and a non-smoker takes place in the presence of a social norm against smoking, how establishments choose to allow (or not) smoking within their dependencies as a response of smokers and non-smokers strategies and analyse whether the government can achieve higher efficiency on the law enforcement if decides to enforce the law against the establishment instead of the smoker themselves.