World building, while certainly not limited to the literary, is a primarily story telling element. We don't do world building in a conversation. @pemerton talked about how getting a letter from a relative has a viceral element and it's true, it does. But, that's because it's part of the real world and all the context is built right in. In a second world, you need to create that context for the reader, or, in the case of an RPG, the player. And, you create that context through literary conceits like world building.
Context is important if you want fictional elements to have emotional resonance. If you're departing from well-known genre territory, you need to build that context into the game so that it becomes familiar. This can be all the GM's job or it can be shared by everyone (collaborative world building).
Well this certainly gets to the heart of it, or to the heart of something at least.
I see two related questions.
(1) Is worldbuilding done, and context established,
for the players? That depends on the system and the table. My experience, going back over 30 years to my early years as a GM, is that players are more invested when the context is something that they have a hand in. This can be as simple as PC backstory that establishes a mentor/master.
And this is something that can be done conversationally. For a somewhat formalised/proceduralised version see eg Fate Core, or PtbA games. But informal approaches have been used for a lot longer than those games have been around.
(2) Does establishing context, and the resulting "pull to action", depend on evocative language/wordcraft? Like [MENTION=5142]Aldarc[/MENTION] not too far upthread, I tend to think that it doesn't.
If the context is something that the GM delivers
to the players, then maybe evocative language is required to get them to buy in. As I posted early in this thread, I think this makes the success of the enterprise rest on the weaker rather than stronger aspect of the game form (ie it depends on one participant's literary capcity, rather than on the shared generation of fiction which, as I see it, is at the heart of post-dungeoncrawling RPGing).
But when the players help supply the context then I think the emotional investment comes from inside rather than outside (to return to a metaphor I used a while ago upthread).
I've been thinking about some comments that appeared some pages back (around page 90, I think) regarding the importance of evocative descriptions in the game. Instead of just calling out die rolls and watching the hit points go down, it's helpful to describe the action from the perspective of the characters. I tend to agree with this. As I've mentioned in this thread and others, I play a lot with new players. I've found that the descriptions are usually what hook new people, especially in combat. Missing your attacks repeatedly can be pretty frustrating, so I make a point of describing what happens with each miss. Subsequently, I encourage players to come up with these descriptions. This makes combat much more engaging and seems to help keep people focused. Indeed, some of those descriptions have been memorable enough to become part of the character's lore, talked and laughed about for many sessions afterward.
I tend to prefer a system that helps generate those sorts of descriptions and the resulting memorable events as part-and-parcel of the adjudication and resolution.
In the session of Prince Valiant I GMed on Sunday one of the knight PCs was trying to ride down a fleeing bandit. The player rolled Brawn + Horse + Gear + Riding (about 8 dice, I think) vs the NPC's Brawn + Agility (7 dice?). I got more successes than the player, and narrated the bandit as leaping onto the back of tjhe PC's steed.
This description changed the fictional situation, so that now the contest was the two wrestling for control of the horse. The new dice pools were put together, and another success for the NPC resulted in the PC being pushed from his horse.
One thing I find frustrating about classic D&D combat (ie hit pont depletion) is that it generally doesn't generate descriptions that actually matter to resolution. That's one reason why I took up Rolemaster as my main game for many years - it's quite different from Prince Valiant (!), but also generates desciptions that matter to resolution. I also found 4e D&D to be a departure from classic D&D in this respect, with combat generating fiction that matters to resolution.