Mass casualty — triage tags; reds treated first; lives saved. Triage: categories (red — immediate — airway, bleeding; yellow — delayed — stable fractures; green — minor — walking; black — expectant/deceased: START — simple), primary survey (ABCDE — airway — cervical; breathing — chest; circulation — bleed — pelvis; disability — GCS; exposure — hypothermia: resuscitate — simultaneously), secondary (head-to-toe — AMPLE — allergies, meds, past, last meal, events; vitals — recheck). Triage is dynamic — reassess. The greatest good — most lives.