game versions versus universe chronology

Welcome!

Yes, you can get a full experience with GC3.  Obviously it won't be the same experience... 

There is a game timeline in the Campaigns screen. 

In general, what happened in the earlier game(s) happened earlier in the galaxy than GC3.  But the games are more iterations of the same concept than consecutive stories.  SD redevelops the internals and takes the occasions to re-do the universe and game design.  (I put that badly.)  Just know that they aren't intentional sequels.

None.  The recent DLC is just adding some Star Control characters and races to the GC context.  Could be some fun alternative races; the old ones do get stale after a while.

Don't worry about it.  There's so much to do before you ever see one, if you do.

Easy to do in GC3.  Just don't select Drenghi as a opponent.  This game isn't locked into a story, except for the Tutorial campaign.  The AIs are strong enough (especially at higher settings) to act quite independent of a story.  And, of course, custom races are pretty easy to do, even without mods.  But play for a while before you head off in that direction.

So with the Gold Bundle, you have all the expansions (I don't).  What are you planning to install?

If you're on Steam, you might want to start with the 3.7 version without Mercenaries or Intrigue.  They complicate things.

I've been deliberately limiting my gameplay so I don't hit the 2-hour limit on the Steam return policy.  I spent most of the 2 hours on the tutorial, and then tried making a new game but felt overwhelmed with not understanding the details of the backstory so I posted here to see if maybe I also needed to get Galactic Civilizations I and II and/or Star Control: Origins while they were still on sale.  I would only want them though if they are happening in the same universe as Galactic Civilizations III (otherwise that's more backstories I have to learn).  If Star Control: Origins takes place in an entirely different universe from Galactic Civilizations III, then I guess the characters from Star Control: Origins only appear in Galactic Civilizations III as the result of some kind of inter-universal teleportation accident? 

A lot of my confusion I am hoping is just because I simply don't have enough hours of gameplay in, and I haven't taken the time to read much of the website metadata and backstories yet on the different civilizations.  But eventually yes I would want to make my own custom civilizations and create my own backstories (and perhaps even a galaxy with nothing but human civilizations, like in Sid Meier's Starships).  I am migrating over from Sid Meier's Civilization V franchise (including Beyond Earth and Starships), so am looking for similar gameplay but set in outer space with new challenges to overcome.

The recent Steam sale offered an exceedingly good deal on the Gold bundle, so yes I got all of the expansions and DLC.  They are currently all installed, so not sure if that helps as a new player or not.  I could try turning off the expansions maybe and just playing the base game, but from what I read online that would be quite a different gameplay experience (one article stated that GalCiv 3 Crusaders is more different from GalCiv 3 than GalCiv 3 was to GalCiv 2), and I figure I should learn how to play with the expansions probably.

You don't really need to understand any backstory.  Just the civilization traits, and what each trait unlocks in the tech tree.  Knowing who the Drengin are is unimportant, but knowing what Slavers can do for your planet IS important.  Gameplay will fix that.  There's really nothing much to read up on (other than helpful posts).

EDIT:  to reiterate, knowing any story from any previous GalCiv is not at all necessary.  And the other game that they put a crossover DLC out for?  I deactivated that DLC.  I found it annoying.  Don't have the other game, don't want the other game.  Doesn't ruin enjoyment of this game.

That as good rationalization as you're going to get.  The real story is that Stardock has rights to the characters, that many people (especially Brad) loves that game and those characters, and thought others would get a kick out implementing them in the GC universe.  Just disable the DLC forget it exists.

^^ This.  🦆

Go ahead play.  This isn't the type of game you can study for; you have to play it to learn it.

Enjoy!  

By the way.  There is a nice manual that seems to discoverable only by accident.  (The 'Manual' button on the main screen is broken.)  Look in your install directory.

E.g. ..\Steam\steamapps\common\Galactic Civilizations III\  for the file GalCivManual_2018.pdf (or something like that).  It will help much more than the wiki or posts here.

Agree with all other posts about not worrying about the backstory.

For reference, if you're thinking about being part of the development of GalCiv4 or simply buying it when people like me have done the un-fun, grindy, hard work for ya , frogboy said when he was introducing Intrigue that he would have vetoed the campaign part of GalCiv3 had he been more involved and you can pretty much expect no campaign in GalCiv4.

Ok first is the Mithilar a human being that slid over from another universe. In the beginning this universe had no sentient beings. He then took a crystal and made five beings. Three were energy, and two were physical. They are known as the Arnor. 

Then the Iconians  evolved. The two physical Arnor were decided on what to do with the Iconians. One wanted to help them grow. The other wanted to destroy them. 

This caused a civil war. The ones that wanted to destroy the Iconians were the Dread Lord's, while the ones that wanted to help the Iconians were the Precursors. Appearently by this time the Drath evolved on Altaria. They are a reptilian species. There are no primates on this planet. The Dread Lord's created a species called the Altarians to serve them on the planet Altaria. The Precursors helped the Drath to escape the planet Altaria.

The Your were created by the Iconians to serve the Precursors. Eventually the Precursors trapped the Dread Lord's in a pocket universe, but not before they made the Yor sentient, and created the Snathi. The sentient Yor turned on the Iconians almost wiping them out. The Precursors disappeared.

Later on other species evolved, including the Drengin, and the Arceans. The learned the Stargate, and made war with each other. The Drengin flew there ships 10,000 years, and conquered the Tori.ans. through gorilla tactics the Torians made it not feasible for the Drengin to rule Toria, and got their independence.

The Arceans meet the Humans, where the humans take the Stargate technology, and combine it with fusion creating the hyperdrive. Beating the Jessiuns by 6 months. The Drengin steal the hyperdrive technology. To fix this the humans give the house perdrive to everyone. In the mean time the Drengin pinn the destruction of the zandar on the humans. The Thalans slide in from another universe at a later date where the hell man's destroy the universe at a later date.

Now comes the galactic war. At least who they knew were in the Galaxy at the time. One side led by the humans. Was Humans, Arceans, Torians, and Altarians against the Drengin, Yor, Drath, and Thalans. While this is happening the Drengin experience another civil war where with the help of the Yor they defeat the Korath, and the Dread Lord's who escape their pocket dimension. Only to win the galactic civil war taking.everyone except earth. Eating Torians.

Now there is another war in three.

There's a timeline in the back of the (very nice) manual. 

And there's one online: https://www.galciv3.com/databanks/timeline

Again, it's mostly "How things got to the current state." rather than an on-going story that you need to follow.