FM 3-21.10 — The Infantry Rifle Company

Overview

FM 3-21.10 governs U.S. Army infantry rifle company operations, establishing how a company of approximately 120–140 soldiers organizes, maneuvers, and fights across the full range of military operations. It bridges FM 3-21.8 (platoon level) and FM 3-0 (operational level).

Company Organization

The standard infantry rifle company consists of:

• Company HQ: Commander (CPT), XO (1LT), First Sergeant (1SG), Headquarters section
• 3 × Rifle Platoons: Each with 3–4 squads of 9 soldiers
• Weapons Platoon: Mortars (60mm/81mm), anti-armor, machine gun sections

The company commander is the lowest echelon with an organic fire support capability (FSO/FO) and a maintenance/supply section.

Offensive Operations

The company conducts three primary offensive forms of maneuver:

Movement to Contact — Used when the enemy situation is unclear. The company moves to develop the situation. Lead elements make contact; supporting elements maneuver to destroy or bypass.

Attack — Deliberate or hasty. The deliberate attack requires full MDMP and rehearsals. The hasty attack exploits opportunity without complete preparation. Both use fire and movement: one element suppresses while another assaults.

Exploitation and Pursuit — Following a successful attack, the company exploits to prevent enemy reconstitution, destroy withdrawing elements, and seize subsequent objectives.

Defensive Operations

Area Defense — The company holds terrain. Platoons occupy battle positions (BPs) that cover engagement areas. The company commander controls fires and manages the reserve.

Mobile Defense — The company uses a fixing force and a strike force. The fixing force canalize the enemy into a prepared engagement area; the strike force counterattacks to destroy the enemy force.

Control Measures

At company level, the commander uses the full set of tactical graphics: phase lines, objectives, battle positions, engagement areas, TRPs, fire support coordination measures. These are produced by the XO and S3 and distributed to all platoon leaders before execution.

Relevance to Dark Dot

Model a company operation in Dark Dot by creating three terrain plans (one per platoon AO) within the same operation, with a master plan showing company-level control measures. Assign each platoon as a team and link objectives to their assigned BPs and engagement areas.