While it is generally understood that people tend not to specialize in specific types of deviance, less is understood about offending specialization and versatility in the context of friendships. Using a large sample of persons nested within friendship pairs, this study's goal is to explore how self-control and social learning theories contribute to an explanation for specialization and versatility in offending among friends. We estimate a series of multilevel, dyadic, mixed-effects models which regress offending versatility onto measures of perceptual peer versatility, self-reported peer versatility, attitudinal self-control, behavioral self-control, and demographic controls. Results indicate that higher amounts of perceptual peer versatility and peer self-reported versatility are both related to increases in versatility among friends. Lower levels of the target respondent's attitudinal and behavioral self-control are also related to higher amounts of offending versatility. However, the peer's self-control shares no relationship with offending versatility - a point which both supports and fails to support self-control theory's expectations about how peer effects should operate. Learning and self-control perspectives both appear to explain offending versatility among friends. However, self-control theory's propositions about how peer effects should operate are contradictory. The concept of opportunity may help remediate this inconsistency in Gottfredson and Hirschi's theory.