When we began publishing (back in 1979), Star Trek was a half-forgotten old television show popular as an afternoon re-run in college towns. We produced much new material before the franchise returned to life, and have continued to be one of the two largest producers of new history, starships, characters, and technology (the other being Paramount itself). As Paramount began producing new materials, the Star Trek Universe and Star Fleet Universe began to diverge, but remained strongly linked. We did not change our games to match their later productions, and they did not change their television series or movies to match our games, but the driving force behind the genre continued to keep the two universes very close indeed. We have no Cardassians or Breen or Dominion (these were created after our contract was signed), but we do have Andromedans and Hydrans and Lyrans. Our Klingons have smooth foreheads, and remain based (as the original Klingons were) on the ruthless Soviets or Nazis rather than becoming mystical Ninja warriors. Romulans have cloaking devices (as do some of the Orion Pirates) but the Klingons do not. Romulans use some Klingon-built warships, but mostly build their own superbly crafted starships. The Gorns (seen in only one original episode) have become friends with the Federation, while the Tholians remain fiercely neutral in that they won't allow anybody into their territory.
The point of a gaming universe is the games! Here is a quick summary:
Star Fleet Battles is the flagship of the Star Fleet Universe. It is a game of ship-vs-ship combat in the 23rd century. When playing Star Fleet Battles, you take command of a starship, squadron, or even an entire fleet of the Federation, the Klingon Empire, or the Romulan Star Empire ... plus over a dozen other empires, each with their own unique style of combat, starships, weapons, technology, and culture.
Federation Commander is the full-color fast-playing game of starship combat.
For a fast-playing full-color card game of starship combat, check out Star Fleet Battle Force. The game can be taught in 10 minutes and played in an hour.
For a more detailed look at the universe, the Prime Directive series of role-playing books provides a wealth of background (maps, governments, religions, legal systems, and everything else) about dozens of new civilizations, plus the option to actually explore the universe as an adventurer, researcher, pirate, or military officer. You can read the books for the background, or use the role-playing rules to explore strange new worlds.
Federation & Empire is the strategic game of the Star Fleet Universe. It is a game of empires in the 23rd century. When playing Federation & Empire, you take the imperial throne of the Klingon Empire, or the Romulan Star Empire, or of other empires, or even the Chairmanship of the United Federation of Planets! You have total command of your empire's economy, production, strategy, and operations.