This cluster-randomized pre-post study examined the effectiveness of Character Playbook, a digitally delivered, universal social-emotional learning (SEL) program, in enhancing social and emotional knowledge and confidence among rural middle school students. Pre- and post-assessments and surveys measured students' knowledge and self-reported confidence related to social and emotional skills. The sample consisted of 128 students from two rural middle schools. Analyses of covariance with multiple imputations to account for missing data revealed that students who participated in Character Playbook demonstrated significantly higher knowledge and more positive confidence toward their social and emotional learning competency than the control group. These findings, with acknowledged limitations, suggest that Character Playbook holds promise as an effective SEL program for rural middle school students, but further research is needed for confirmation. The study provides valuable preliminary insights into how a brief, digitally delivered, universal SEL program could benefit students in rural classrooms.