Many computer games ask us to act in ways which would be morally unconscionable, were we to so act in the physical world. Within the game world, these actions are seen as unproblematic. As such, simple translations of concepts such as assault and murder from the physical to the virtual fail. Killing an opponent in World of Warcraft is not morally equivalent to killing someone in the physical world. However, this does not mean that virtual murder is impossible. Rather, the social reality of particular game-worlds is distinct from, but connected to, the social reality in which we operate in the physical world. In this paper, I examine the ways in which immoral conduct can occur in virtual environments. I discuss the particular problems of the ‘magic circle’ model of gaming in the context of online, massively interactive computer gaming as popularised by World of Warcraft, Rift, Aion. (Castronova 2005, Zimmerman 2012) The most important of these problems is perhaps the lack of distinction many participants in these worlds make between their avatars and themselves. (Lehdonvirta, 2010) This connection between the virtual and physical worlds enables us to generate a moral framework for guiding action within virtual worlds. With this background established, I argue that it is the subversion of game mechanics and intentions which generates the wrongness of particular types of action within virtual worlds.