In this grounded theory study, 19 teachers were interviewed and then, in constant comparative fashion, the interview data were analyzed. The theoretical model that emerged from the data describes novice teachers' tendencies to select and implement differing strategies related to the severity of student behavior. When confronting mild student misbehaviors, teachers perceived their behavior management strategies to be more effective and reported implementing such strategies with greater consistency. When facing more severe misbehaviors, novice teachers perceived their management strategies to be largely ineffective and reported implementing them inconsistently. Ultimately, this grounded theory postulates that when novice teachers lack relevant college coursework their default behavior management strategies may be effective for addressing mildly disruptive student behaviors. Furthermore, the theory supports the prediction that preservice teachers might benefit most from specific training in dealing with more severe misbehaviors. Implications for teacher education and professional development are discussed.