There is no need for a detailed world to provide a base for consistent scenes and encounters.
Yes! Exactly!
I was just reading through all the posts from today to check if someone already made the point I wanted to make, and you did.
I would say the main
function of worldbuilding is to create situations. And great worldbuilding creates consistent situations.
When we look at other forms of fiction like books, movies, tv shows, and videogames, I think what mostly makes us think "I would love play in that world" really is "I would love to be in that position and deal with this situation in a game". When a world is engaging and captivating, it's because we start to recognize that there are certain rules for how things are happening in this world. And by learning these rules and patterns, we can understand what the protagonists are doing and why they are acting the way they do, and we can anticipate what will happen as result of that.
When the Emperor tells Luke "Let your hate flow!" and we want to shout at Luke to not give in to his anger, we feel engaged because we have learned how the Dark Side of the Force works. The realization that we understand what's going in a situation that makes absolutely no sense to someone who hasn't been innitiated creates a very rewarding experience. Especially when we're in an RPG and we can actually use our new understanding to gain an advantage.
I think great worlbuilding challenges the players with a setting in which events happen according to certain patterns that are not automatically obvious, but which can be recognized and understood by interacting with the world. And the greater the understanding is, the more efficient the PCs can act.
I think the main application of this is to have consistent and understandable patterns for how certain types of people in the setting tend to react to certain things. When players are able to recognize to which faction, culture, or society an NPC belongs, and can make informed predictions for what kind of things will make that NPC happy, proud, agreeable, angry, or hostile. When you have a good guess how you can steer NPCs to perform certain actions. To bribe, scare, or fool them.
This can be done by basing these things on a backstory for whatever group an NPC belongs to, but that backstory can be really very short and simple.
BioWare in their prime had this nailed down. The Mass Effect series has a huge amount of Database entries where you can read up on stuff with additional information, but none of it is necessary to understand the relationships between certain groups. The story that is important is extremely simple.
"Quarians developed artificial intelligence and had to flee their homeworld in a Robot-Revolt, and they've been living on space-ships and in poverty for the last 300 years" is all you need to know to understand everything that happens in the three games revolving around Quarians and Geth. And they really got a lot of mileage out of that one-sentence history. The situation with the Krogan is a bit more complicated, but you get a lot of interesting situations and interactions out of two minutes of backstory. And neither of those two stories involves a single named character, specified location, or a specified timeline.