The Maasai age-grade system organizes men into cohorts that move together through life stages: boyhood, warrior (moran), junior elder, senior elder. Each stage has duties, privileges, and rituals. The moran stage, when young men live apart, guard cattle, and prove their courage, is the most visible. Age-grades create bonds that last a lifetime, enforce social discipline, and distribute authority across generations. The system is under pressure from modern education and economy, but it persists, adapting while holding the core structure intact.