Expeditionary Forces

The Expeditionary Forces provide direct ground combat capability when needed, insurrection and riot control where anticipated, and site security of Star Fleet (and UFP) assets outside of UFP territory. They may also be called in to work alongside Star Fleet Security within the UFP. The commanders of an expeditionary force report directly to the Commandant of the Star Fleet Marine Corps, so there is no Expeditionary headquarters element between them.

An expeditionary force will be comprised of up two Marine divisions, but oftentimes will deploy without the entire organization, as the situation merits. Similarly, if the situation requires a significant expansion of the Corps, any (or all) force(s) may control many divisions in order to accomplish the requirements of whatever front on which they are responsible. In peacetime, a force command element (headquarters) may be located on a sector capital, with its component divisions located on other planets (usually within the same or neighboring sectors).

Expeditionary Forces are commanded by a Lieutenant General, with a Major General as the executive officer.

An Expeditionary Force (Echelon III) is broken down into the following hierarchy (with 2 divisions):

Marine Division (Echelon IV):
- 2 Marine brigades:
  - 18 Marine battalions (18,000 Marines)
  - 6 Mobile Marine Artillery battalions (30 batteries of 6 guns each & 720 total artillery crew)
  - 2 Marine Armor battalion (120 medium tanks & 480 troops)
  - 2 Combat Engineer battalions (1,200 Seabees)
- 2 Mechanized Marine battalions (120 IFVs / light tanks & 360 mechanized crew)
- 1 division Marine Command element, 2 brigade Marine Command elements, and 6 regimental Marine Command elements

The expeditionary division components may be separated between member planets within a sector or co-located on the same planet (usually, in this case, the sector capital). They are commanded by Major Generals.

Marine Brigade (Echelon V)
- 3 Marine regiments:
  - 9 Marine battalions (9,000 Marines)
  - 3 Mobile Marine Artillery battalions (15 batteries of 6 guns each & 360 total artillery crew)
- 1 Marine Armor battalion (60 medium tanks & 240 troops)
- 1 Combat Engineer battalion (600 Seabees)
- 1 brigade Marine Command element and 3 regimental Marine Command elements

The expeditionary brigade's components are often co-located on the same garrison planet, but separated (when possible) around its surface at differing camps. Each brigade is command by a Brigadier General.

Marine Regiment (Echelon VI):
- 3 Marine battalions (3,000 Marines)
- 1 Mobile Marine Artillery battalion (5 batteries of 6 guns each & 120 total artillery crew)
- 1 regimental Marine Command element

The expeditionary regiment is intended to be the smallest deployed unit to a war zone/planet. However, they may be deployed in battalion strength (or even smaller units), if the situation does not warrant (or even prevents) larger deployments. Regiments are garrisoned as a unit within one camp or a series of co-located camps and are commanded by a Colonel.

An expeditionary force will also be assigned an air combat element of an appropriate size, deployed by Aerospace Operations, and usually comprised of a mobility unit commensurate to the size of the force, plus a fighter unit (usually from the Air Combat Branch). The element may be reduced in size once assault landings are completed, though a component is usually provided to allow sufficient planetary mobility and air coverage.

While Marine units may have informal names (after their garrison planets, symbolic terms and totems or battles), their official names are regimented and logical. Expeditionary Forces are numbered sequentially in (nominally) single digits (ex: 1st Expeditionary Force). Marine Divisions are numbered with 2 digits, also sequentially, starting with the 10th Marine Division. As whole divisions are moved between forces, their subordinate commands will not change and are numbered according to their parent division. Marine Brigades are numbered with 3 digits, the first 2 comprised of their division's number (ex: 101st Marine Brigade), while Marine Regiments are numbered with 4 digits, the first 3 comprised of their brigade (ex: 1011th Marine Regiment). Battalions assume the name of their regiment, followed by a Greek letter (alpha, beta, gamma) designation (ex: 1011th Alpha Battalion).

Note: Expeditionary Force commanders are named NPCs (as they may go on to be the Commandant) or higher offices. The force executive officers and all subordinate commanders are unnamed NPCs.