In my talk I will discuss the idea of “roaming” from a phase space perspective. In particular, roaming  is described as an alternate reaction pathway in phase space that is guided by specific types of phase space structures. I will illustrate this by considering roaming in formaldehyde and demonstrating the existence of the phase space structures that “select” between roaming and dissociating trajectories. If time permits, I will discuss the generality of this approach and roaming in other systems (e.g. ketene isomerization, ion-molecule reactions).