The current studies examined how the Dark Triad personality traits (i.e., Machiavellianism, narcissism, and psychopathy) facilitate the strategic structuring of an individual's social environment in terms of same- and opposite-sex friends. In one study using normative questions ( N = 267) and another using a budget-allocation task ( N = 114), we found that the Dark Triad traits were associated with choosing friends for strategic purposes and to create a volatile environment. Narcissistic individuals reported relatively more reasons to form friendships, such as shared interests, makes me feel good, and intelligence. Women high in narcissism chose same-sex friends who were attractive and women high on Machiavellianism chose same-sex friends who have social status. Men high on psychopathy devalued traits associated with good social relationships in favor of friends who could facilitate their mating efforts and to offset risks incurred in their life history strategy. Results are discussed using the selection-manipulation-evocation framework for explaining how personality traits interact with social environments and integrated with findings from evolutionary biology.