The activation relationship theory, primarily focused on parental stimulation of risk-taking along with parental control during exploration, predicts that boys will be activated more than girls by their fathers. This theory may explain why fathers engage in rough-and-tumble play (RTP) with children more frequently than mothers, especially with boys. Thus, the main objective of this study is to verify the existence of a positive association between the father-son activation relationship and the frequency of father-son RTP. Given that RTP is thought to encourage the development of competition skills, it was anticipated that no association would be found between the father-child attachment relationship and the frequency of father-child RTP. The Strange Situation (SS) and Risky Situation procedures were conducted with 58 father-child dyads (22 boys and 36 girls) during toddlerhood to evaluate the attachment relationship and the activation relationship, respectively. The fathers completed a play questionnaire when children were three years old to assess RTP. Results show that the more optimally activated boys are by their fathers in toddlerhood, the more they engage in RTP with them at the age of three years. As it was anticipated, there is no association between the father-child attachment relationship in toddlerhood and the frequency of father-child RTP in the preschool period. In addition, the tendency of avoidant children to engage in more RTP with their fathers supports the hypothesis that the SS evaluates something different when used with father-child dyads instead of mother-child dyads. (Contains 4 tables and 1 figure.)