This publication provides introductory technical guidance for civil engineers, structural engineers and other professional engineers and construction managers interested in the alternate path approach to preventing progressive collapse of buildings due to seismic or explosive incidents. Here is what is discussed: 1. INTRODUCTION, 2. ALTERNATIVE RATIONAL ANALYSIS, 3. LOAD AND RESISTANCE FACTOR DESIGN FOR ALTERNATE PATH METHOD, 4. PRIMARY AND SECONDARY COMPONENTS, 5. FORCE- AND DEFORMATION-CONTROLLED ACTIONS, 6. EXPECTED AND LOWER BOUND STRENGTH, 7. MATERIAL PROPERTIES, 8. COMPONENT FORCE AND DEFORMATION CAPACITIES, 9. REMOVAL OF LOAD-BEARING ELEMENTS FOR THE ALTERNATE PATH METHOD, 10. STRUCTURE ACCEPTANCE CRITERIA, 11. LINEAR STATIC PROCEDURE, 12. NONLINEAR STATIC PROCEDURE, 13. NONLINEAR DYNAMIC PROCEDURE.