TBS Phase III Exam Questions and Answers 2026 | 100+ Marine Corps Offensive & Defensive Operations Questions | Flanking Attacks, Machine Guns, Obstacles, IEDs & Engineering Operations | The Basic School

This focused TBS Phase III Exam study guide contains more than 100 exam-style questions and verified answers covering offensive operations, defensive planning, machine gun employment, obstacle integration, combat engineering, improvised explosive device (IED) awareness, fire support coordination, and tactical control measures taught at The Basic School (TBS). Designed for Marine Corps officers, officer candidates, NROTC midshipmen, PLC candidates, OCC candidates, infantry leaders, and professional military education students, this resource provides a concise yet highly effective review of the tactical concepts and doctrinal principles most frequently assessed during TBS Phase III examinations and field leadership evaluations. The question-and-answer format supports rapid knowledge retention while reinforcing practical battlefield decision-making skills. A major emphasis of the guide is offensive operations and maneuver warfare doctrine. Students will review assault positions, probable lines of deployment (PLD), leader’s reconnaissance procedures, support-by-fire operations, flanking attacks, limited visibility operations, tactical control measures (TCMs), and offensive maneuver planning. The material explains how Marine leaders confirm planning assumptions through reconnaissance, coordinate maneuver forces with supporting fires, and exploit enemy vulnerabilities through surprise, speed, and positional advantage. Special attention is given to the tactical advantages of flanking attacks, support-by-fire occupation methods, and the principles that enable effective offensive combat operations. The document provides extensive instruction on machine gun employment and fire control measures. Students will study classifications of machine gun fire in relation to the ground, the gun, and the target, including grazing fire, plunging fire, fixed fire, traversing fire, searching fire, and enfilade fire. Additional topics include machine gun displacement methods, echelon displacement, unit displacement, target engagement considerations, and the integration of machine guns into offensive and defensive schemes of maneuver. These concepts are essential for maximizing battlefield coverage, suppression, and combat effectiveness during infantry operations. Combat engineering and obstacle operations receive significant attention throughout the study guide. Students will review obstacle breaching doctrine, tactical obstacle effects, obstacle integration principles, survivability considerations, and reinforcing obstacle planning. Topics include the tactical tasks of Fix and Disrupt, covered-by-fire requirements, protective wire obstacles, obstacle employment principles, and the role of engineering support in shaping the battlefield. The material reinforces how properly integrated obstacles slow, channel, fix, and disrupt enemy forces while enhancing friendly maneuver and defensive effectiveness. Defensive operations planning is another key area of study. Students will examine stand-to procedures, sectors of fire, command post placement, engagement area considerations, survivability planning, and defensive security measures. The guide explains how Marine leaders establish defensive positions, allocate fires, organize defensive sectors, and position command elements to maintain situational awareness while influencing the battle. These concepts support defense-in-depth planning and the effective employment of combat power during defensive operations. The material also delivers important instruction on counter-IED awareness and threat recognition. Students will review IED network structures, emplacement techniques, operational effects of IED campaigns, common emplacement locations, IED indicators, triggering mechanisms, switch components, Trojan Horse devices, and the role of emplacers within insurgent networks. Additional coverage includes Company Level Intelligence Cells (CLIC), threat identification, route planning considerations, and mission planning factors designed to reduce vulnerability to improvised explosive threats. These topics reflect lessons learned from modern combat operations and counterinsurgency environments. The content aligns closely with official Marine Corps doctrinal publications and professional military education references, including MCDP 1 Warfighting, MCWP 3-1 Offensive and Defensive Tactics, MCWP 3-15.1 Machine Guns and Machine Gun Gunnery, MCWP 3-17 Engineering Operations, Marine Corps Counter-IED guidance, Fire Support doctrine, and TBS tactical instruction materials. These publications establish the doctrinal foundation for maneuver warfare, obstacle integration, machine gun employment, battlefield survivability, and tactical leadership throughout Marine Corps operations. This document is highly relevant for TBS students, Marine Corps officers, officer candidates, infantry officers, weapons platoon commanders, machine gun section leaders, combat engineers, intelligence officers, fire support coordinators, NROTC midshipmen, PLC candidates, OCC candidates, military academy students, and professional military education participants preparing for TBS Phase III examinations, officer qualification assessments, leadership evaluations, promotion boards, or advanced tactical training. It is particularly valuable for individuals seeking a focused review of offensive operations, machine gun employment, obstacle integration, defensive planning, engineering support, and counter-IED operations. Keywords TBS Phase III, TBS Phase 3 exam questions, The Basic School, Marine Corps tactics, offensive operations, flanking attack, leader's reconnaissance, support by fire, assault position, probable line of deployment, PLD, limited visibility operations, tactical control measures, maneuver warfare, machine gun employment, grazing fire, plunging fire, fixed fire, traversing fire, searching fire, enfilade fire, unit displacement, echelon displacement, obstacle breaching, combat engineering, obstacle integration, tactical obstacle effects, disrupt, fix, covered by fire, protective wire obstacles, survivability, defensive operations, stand to procedures, sectors of fire, command post placement, engagement area development, defense in depth, counter IED operations, IED indicators, Trojan horse IED, switch component, emplacers, CLIC, Company Level Intelligence Cell, route planning, threat recognition, fire support coordination, Marine Corps doctrine, United States Marine Corps