Rank Structure in Starfleet

A Brief Description of Titles and Duties

Enlisted Ranks

Spacehand 3rd Class (E-1) 
These are fresh recruits and hold this bottom rank for their first year in Starfleet. Casually called “Greenhorns” or “Rookies/ Rooks” They are shuffled from assignment to assignment until their first evaluation and permanent assignment 

Spacehand 2nd Class (E-2)
Often referred to casually as “trainees”, these are Spacehands who have been given their permanent assignment.  Once they have been assigned a position, a formal request must be filed to be reassigned to a new position. This is primarily a training rank and once the Spacehand can demonstrate full proficiency in their assigned duties (usually 1-3 years, depending to the position assigned) they are eligible for Promotion 
 
Spacehand 1st Class (E-3) 
These Spacehands make up the bulk of the enlisted personnel in Starfleet. Referred to casually as “Able Spacehands” or “Specialists” the Spacehand 1st class is normally assigned to all of the mundane and routine duties of their post.  Tactical Spacehands have Guard Duty at sensitive locations, Science Spacehands ensure that laboratory facilities are clean and prepared for their designated use, Engineering Spacehands are assigned the minor technical issues which crop up in the course of operations and so on and so forth.  When a Spacehand’s Tour is complete, they are often encouraged to test for promotion to Petty Officer 

Petty Officer 3rd Class (E-4) 
The lowest level of leadership ranks, the Petty Officer 3rd Class is, much like the Spacehand 2nd Class, a training rank.  P.O. 3rd Class crew are placed in charge of very small units of Spacehands and evaluated on their ability to successfully accomplish group-oriented goals. 
 
Petty Officer 2nd Class (E-5) 
Petty Officer 2nd Class are often assigned a consistent squad of Spacehands to lead, 4 to 6 hands normally.  The P.O. 2nd Class are mentored by a Chief or Senior Chief Petty Officer in skills of team building and group projects.  Much like the Spacehand 1st Class, the assignment for the teams are all postings of mundane and routine duties. 
 
Petty Officer 1st Class (E-6) 
Petty Officer 1st Class are often assigned squads of 6-12 crew and is often expected to work on projects independent of supervision from higher ranks until the project is complete.  The additional crew assigned to their teams are often Spacehand 3rd and 2nd Class and in addition to leading their teams, the Petty Officer 1st Class trains the recruits assigned to them. 

Chief Petty Officer (E-7) 
Often referred to casually as “Chief”, the Chief Petty Officer is often assigned to lead a section, with all enlisted personnel answering to them.  They have multiple varied duties and projects to which they assign teams. The Chief Petty Officer is also the lowest enlisted rank to have regular interaction with Officer Ranks. It is possible for an individual to spend the majority of their Starfleet career as a C.P.O. Chief Petty Officer is also the lowest rank where refusing promotion does not negatively reflect on their overall career or prospects for future promotion. 

Senior Chief Petty Officer (E-8) 
The Senior Chief are assigned broader responsibilities.  Senior Chief Petty Officers form the majority of enlisted leadership in a department, receiving their direction from Lieutenants (O-2 and O-3) in their department.  The Senior Chief Petty Officer often have a great deal of institutional knowledge since it takes a dozen years (on average) to achieve this position and often more.  The Senior Chief Petty Officer is also the highest rank that an individual can test to without regard to positional openings. 
 
Master Chief Petty Officer (R-5) 
The Master Chief Petty Officers are Departmental Leaders, normally there is only one Master Chief post available in any given department, and this post needs to be vacant before it can be filled again.  The Master Chief is also a direct liaison to the Department Head (most often a Lieutenant Commander) and is a part of that officer’s permanent staff.  At this rank, though the Master Chief is enlisted, their seniority is often recognized above most Lieutenants. 

Officer Ranks 

Ensign (O-1) 
Ensigns are the rank assigned most Academy graduates.  Ensigns spend their first year or two being shuffled between departments, assignments and posts, receiving on the job training specific to their potential duties.  After this training period, the Ensign is assigned their permanent posting and duties.  Ensigns remain very fluid in their assignments, being free to request transfer between departments to expand their breadth of experience. 

Lieutenant, Junior Grade (O-2) 
The Lieutenant j.g. is the lowest officer rank commonly given leadership responsibilities, serving as a section officer over enlisted personnel.  The Lt j.g. are responsible for most of the bureaucracy in a department, filing reports, managing departmental schedules, and coordinating projects between different sections. 
 
Lieutenant (O-3) 
Lieutenant is the most populous officer rank and is commonly the lowest rank posted to permanent assignment to a Command Position (often referred to as a “Bridge Officer” on board starships).  Departmental Lieutenants are often supervisors over the various Lt j.g. in their assigned sections. 

Lieutenant Commander (O-4) 
Lt Cmdr is the first of the “Senior Officer Ranks”. Commanders of a ship, starbase or facility will have a senior staff answerable directly to them, of which Lieutenant Commanders make up the majority.  Lieutenant Commanders fill all Department Head positions and command all long-term projects in a facility or on board a ship or starbase.  In situations where a ship or facility is commanded by a rank O-5 Commander, the executive officer is drawn from the Lieutenant Commanders on board.  As Senior Staff, Lieutenant Commanders are often Officers of the Watch and are in the chain of command, assuming command as 2nd, 3rd, 4th officers etc… 
 
Commander (O-5) 
Commanders are normally the Executive Officer on board a ship, starbase, or facility.  In situations where no officers of Captain (O-6) rank are available to assign to command, a Commander will be assigned to the post.  In most cases, Commander is a rank that is a preparatory position for full command. This makes Commanders very transitory very quickly promoting into Captain Rank. 
 
Captain (O-6) 
Captain is the highest field rank an individual can promote to.  Captains are in direct command of their postings.  Captains are never permanently assigned to the same posting as other Captains.  In situations where a visiting Captain is present on a mission or project, the visiting officer is placed outside the chain of command, to better prevent any conflicts of authority. Captain is commonly the pinnacle of an individual’s Starfleet career, and most captains will retire after years in this rank and multiple commands. 

Flag Officers

Commodore (O-7) 
Commodores are the lowest flag officer rank.  Commodores are the only flag rank that are permanently assigned to command of a “field post” (being a starship or outpost).  Commodores in these command postings have all of the duties of any commander, but have expanded responsibilities that extend over multiple postings, like a task force of starships or the multiple postings of an outpost (like the outpost itself, orbital facilities, system defense boats, etc…)  

Rear Admiral (O-8) 
Rear Admirals serve in postings that command permanent Starfleet fleets or sectors. At this rank, the overall duties preclude the direct command of any single post.  The direct commander of a single ship in a fleet or a single base in a sector, will receive strategic direction from the Admiral, but the authority with regards to the operation of the ship remains solely the responsibility of the post commander.  Thus, when on board a ship, a “Flag Bridge” will be established for the Admiral, with resources that allow the Admiral to execute the greater strategic operation.  In practice, most Rear Admirals find this arrangement to be distasteful, and prefer to operate from a Starbase if at all possible, where they can retain direct command as well as operational strategic command. 
 
Vice Admiral (O-9) 
Vice Admirals command entire fleet groups assigned to a sector.  They administer their command from a command headquarters located in a sector’s capital system. Or from  Starfleet headquarters on one of the Federation’s primary worlds in the region.  Vice Admirals are the architects of Starfleet’s strategic policies and it is through their authority that Fleet Missions are assigned. 
 
Admiral (O-10) 
The highest rank in Starfleet, Admirals have strategic authority over entire theaters of operation.  These theaters are most often defined by the neighboring polities to the Federation (the Romulan Theater, the Cardassian Theater, etc…).  Admirals administer their theaters from core Federation systems like Earth or Tellar. 

Fleet Admiral (O-11) 
There is only one Fleet Admiral in Starfleet at any given time.  The Fleet Admiral is the Commander-in-Chief of Starfleet and operates from Starfleet Headquarters on Earth.  The Fleet Admiral is a Cabinet Secretary in the office of the Federation President they advise and directly report to the serving President and serves “at the President’s pleasure”.  The Fleet Admiral directs the overall policy of Starfleet, deciding on how the institution will apply it’s resources over the course of the Admiral’s tenure. This is a mostly political position, not only representing Starfleet in the Federation President’s cabinet, but advocating for Starfleet within the Federation Legislature.