21st Century Skills encompass life capabilities for individuals to work and prosper in complex environments. Resilience encapsulates positive behavioural adaptations acquired through optimised exposure to outdoor adventure education (OAE). This study examined the efficacy of one-week OAE residentials upon young people's resilience, psychological well-being, and vocational skill development. Importantly, it identified OAE components which best cultivated their learning. Significant gains were reported in the resilience and well-being of 622 diverse adolescents across three timepoints. From below average baseline scores, resilience and well-being increased by 36% and 23% respectively. These increases were largely retained one month later. Camp-based experiences including mastering new skills, solving problems, and being inspired by nature predicted heightened resilience and well-being. These results supported the positive development of 21st Century Skills which promote individual and collective functioning and are protective of stress. Embodied challenges in real-world contexts enable vulnerable young people to re-adjust, grow, and persevere.