Inner Sphere Infantry Organization
The organization of Infantry within the Inner Sphere can trace it roots back to the Star League Defense Force. All of the Great Houses and most Mercenaries mimic the structure of the SLDF, including their infantry forces, and have maintained this organization long after the Star League collapsed. Though located within the Inner Sphere, ComStar and Word of Blake infantry are organized on entirely separate lines, and there is some variation out in the Periphery.
 Unit Organization
The smallest organizational unit, Squads are normally composed of seven soldiers, including a non-commissioned officer (NCO) and junior NCO to lead them. However, squads are rarely deployed individually, instead operating as part of a platoon. Typically, squads are categorized as either maneuver or support squads. Maneuver squads are armed with their typical small arms, in addition to any light squad support weapons such as a Compact Grenade Launcher and Portable Machine Gun. Support squads generally carry larger weapons, such as Support Lasers or SRM Launchers, in order to provide the maneuver elements with fire support.
However, some mechanized units make use of a smaller squad size, due in part to the size of their APC or IFV. Mechanized squads mounted in hovercraft number only five soldiers, while those in wheeled vehicles number six.
The Platoon is the smallest unit most commonly committed to the battlefield, though it will often break off into its constituent squads during battle. For most infantry types, the platoon is composed of four squads, three maneuver and one support, for a total of twenty-eight soldiers. The platoon is led by a junior commissioned officer, typically a Lieutenant assisted by a senior NCO. They command the unit from the support squad and assume the positions normally filled in by the junior NCOs. In some platoons, a Field Medic takes the place of one or more of the squad support weapons.
Jump infantry platoons only contain three squads, for a total of twenty-one soldiers, and lacks a dedicated support squad. In addition, mechanized platoons include additional personnel to operate their vehicles, typically one APC/IFV per squad.
A Company consists of three platoons and is normally led by a Captain. An attached command squad is often used to assist the commanding officer in coordinating the company, though this varies depending on organization. In some cases, additional units can be attached to the company to provide support.
Composed of three companies, the Battalion is commanded by a Major or Colonel. A command platoon was standard in the SLDF, though this too varies with each military. Infantry battalions often act in support of BattleMech regiments.
The Regiment is the largest infantry formation still in use, composed of three to four battalions and led by either a Colonel or General. A command company is common to allow the commander to better direct his forces, though this varies between organizations. An infantry regiment could include other support units, though in modern times usually it is integrated into a Regimental Combat Team.
Infantry Brigades were formed of three infantry regiments, in addition to attached support units. Brigades were last used by the SLDF before its dissolution.
The largest formation used by the SLDF, infantry Divisions were either foot, mechanized or jump. Each consisted of two infantry brigades and a third BattleMech brigade, as well as support units such as an AeroSpace Fighter wing. The use of the division died with the SLDF.
Like the Successor States, many of the powers within the Periphery follow the same standard in regards to their infantry forces. However, the Marian Hegemony uses a different measure of organization: foot and motorized infantry platoons are composed of ten squads of ten soldiers each, while jump platoons contain five squads of ten soldiers each. Within the Taurian Concordat, these same platoons are composed of three squads of ten soldiers each.
 Specialist Troops
Most specialist infantry units operate in squads of up to ten soldiers, with the number per platoon varying by their job description. Combat Engineer and Mountaineer platoons consist of two squads, while paratrooper platoons contain three. Space marines and SCUBA troops operate in platoons of four squads, with motorized SCUBA troops fielded in platoons of two six-man squads.
- ↑ 1.0 1.1 1.2 The Star League, p. 134
- ↑ 2.0 2.1 2.2 2.3 BattleTroops, p. 34
- ↑ 3.0 3.1 3.2 Total Warfare, p. 34
- ↑ 4.0 4.1 TechManual, p. 147
- ↑ Tactical Operations, p. 27
- ↑ 6.0 6.1 Tactical Operations, p. 340