A Commanding Officer is the highest ranking member of a chain of command.

Usually, these inviduals command a Space Station, Starbase or Starship of a military nature.


Commander Rank. These officers typically command a low-level Space Station, Starbase or Starship


Captain Rank. These officers are the elite of Starfleet Officers. Roughly 80% of Starfleet Captains are in command of Starships, Space Stations or Starbase


Rear Admiral (Lower Half) Rank. The first Admirality rank, these officers are 90% of Starfleet Command administrators.


Rear Admiral (Upper Half) Rank. The second Admirality rank, these officers typically command a Federation task force.


Vice Admiral Rank. The third Admirality rank, these officers are typically placed in command of an entire sector or department, such as Starfleet Operations.

Someone runs the sim. For live Star Trek sims, this person is usually called the "CO" or Commanding Officer. They can also be called the GM or Game Master. The term Game Master comes from the time before computers and dice role playing games like Dungeons and Dragons.

A CO or GM is responsible for planning the game, making up the plots, setting a schedule, sending out notices, prompting players, etc. In short they are responsible for keeping it going. In recent times, this person may also create and run a web page for the players in the game.

Of course any of these responsibilities can be delegated to someone one else, but the overall running of the game is the job of the CO/GM. (An older term, DM, may be familiar to some people. In Dungeons and Dragons, the DM was the Dungeon Master, who made and ran the dungeons and other parts of the game.)