Not the klingons, they eat their Gagh live.

Science Fantasy is usually a fantasy story in a setting typically associated with scifi. The classic example is Star Wars; it’s it a world with spaceships and lasers, but it’s about space wizards having swordfights.

Every custom, every belief, every fashion, every turn of speech?

No, of course not. Why would anyone waste effort on infinite irrelevant details? But everything there is to know, I know.

I do believe that player should be able to gain a basic understanding of the cultures their characters come from. The question is how much information can they get, and process?

You give them an overview at the start with the information you guess might be relevant or interesting to them, and supplement it during the game as necessary.

Part of the fun of DMing for me is in homebrewing cultures…or, more accurately, homebrewing factions that have a culture.

Besides which, there are some fundamental flaws in your premises:

You assert that a counterpart culture is easier to understand than an original one. I 100% understand any culture I make up, definitionally. On the other hand, neither I nor anyone else at my table can say the same about any IRL culture. Even members of a given IRL culture can never fully understand the totality of it.

You also say

[if] you create fantasy ancestries from scratch, you need to convey all that information to the players.

And I don’t think that’s true. Players don’t need to know everything about a culture to interact with them. In many cases, the player characters are themselves unfamiliar with that culture, in which case any mystery, mistakes, miscommunications etc are valuable in-character roleplay. And when the PCs would be familiar with a relevant aspect of a given culture, you can simply tell them that detail, no need to loredump everything. (Eg “I beg for mercy” “Your character knows that The Southern Pirates are notorious for never taking prisoners, are you sure you want to try that?”)

cloaca

<3

I’m not making fun of you I just thought it was a funny word :) Also, sorry about your butt.

gastroentomologist

No no, they didn’t do that until TNG

The DM gave him an OP magic item to compensate for his crappy build

Your worn items just kind of morph into your body when you wildshape. You don’t have to strip naked to go from humanoid to animal, for instance.

Magic is rare in most settings.

RAW that wouldn’t do anything though.

I don’t really go on other networks, is there drama about .ml?

If you don’t want to do a one-shot, I still recommend keeping it short. 3-5 sessions perhaps. Just to dip a toe in and even out the kinks, and be able to feel good that you completed something. Decide if you want to commit to a big sprawling campaign after the first little demo campaign.

The federation changed forever on the day the Enterprise discovered the Planet of Chocolate Air

Pretty terrible movie, all things considered, but it does have a very satisfying ending.

Only the Doctor was sentient

I think it’s fine if they act like highschoolers in a show for highschoolers. It just means that’s not a show that’s for me.