This paper provides an analysis of collusion in oligopolies from a game-theoretic perspective. It first provides a basic survey of oligopoly models and then uses game theory to analyze non-cooperative or tacit collusion in these models, in a way that should be accessible to undergraduate economics students. In this way, the author characterizes the conditions under which collusive behavior might occur. Importantly, this paper draws its conclusions by using relatively basic methods with which those foreign to the subject should be able to understand.