In classic D&D, the dungeon was a type of puzzle. The players had to map it, by declaring moves (literally) for their PCs. The players, using their PCs as vehicles, had to learn what was in there: this was about inventory - having enough torches, 10' poles, etc - and about game moves too - searching for secret doors, checking ceilings and floors, and so on. And finally, the players had to try and loot it while either avoiding or defeating the monsters guarding the treasures and wandering around the place - this is what the combat mechanics were for.
The game is something of a cross between a wargame and a complex refereed maze. And *worldbuilding* is all about making the maze. I get that.
I'm not quite sure you do.
Worldbuilding is about making the universe and world and kingdom in which the maze is located; and about making the history of how these things (and maybe the maze, too) came to be what they are, and about making the cultures and peoples and creatures and climates and terrain that a PC encounters en route to the maze.
By the time you get down to designing the dungeon maze itself you've already done 99% of the work. (or, if using a pre-fab setting e.g. Greyhawk, had 99% of it done for you)
But most contemporary D&D isn't played in the spirit of classic D&D: the players aren't trying to map a maze; when it comes to searching, perception and the like there is often an emphasis on PC skills (perception checks) rather than player game moves; there is no clear win condition like there used to be (ie getting the gold and thereby accruing XP).
In the classic game, alignment (and related aspects of character motivation) become components in, and establish the parameters of, the puzzle: if I find a prisoner in the dungeon, should I be rescuing her/him (after all, my PC is lawful and so I might suffer a GM-imposed penalty if I leave a helpless person behind)? Or is s/he really a succubus or medusa in disguise, trying to take advantage of my lawful foibles? This is one reason why divination items like wands of enemy detection, ESP medallions and the like are so prominent in classic D&D - they're "game components" which, once obtained, allow a clever player to make better moves and so increase his/her chance of winning the game. And their function relies upon the GM having already written the dungeon, and having already decided what the truth is about the prisoner.
Cool stories, bro, but nothing to do with worldbuilding. These are more related to game-mechanic-rules system building, which most worldbuilding doesn't really care about except as regards nailing down the setting's vague historical era (medieval, modern, far future, etc.).
I'm expected to develop my character, and to care about his/her motivations, for their own sake. This is part of the standard picture of what it is to be a good RPGer.
Again this has almost nothing to do with worldbuilding. Character building, maybe, but that's yet another different thing; and again its only real interaction with worldbuilding is the world's intended historical era defining what the character can be and-or do.
Worldbuilding gives you the stage on which you play out all this character development.
So, given these difference between typical contemporary play and "classic" play, what is world building for?
It gives the game a backdrop, a history, a sense of continuity and consistency and place.
And here's a final thought: In
this blog post, Luke Crane has interesting (and very enthusiastic) things to say about playing Moldvay Basic. He also asserts that "the beautiful economy of Moldvay's basic rules are rapidly undermined by the poorly implemented ideas of the Expert set." I think at least part of what he has in mind there is that Expert-style wilderness adventuring doesn't establish the same clear framework for play. There is no clear maze, and so no clear parameters for establishing puzzles to solve in avoiding or defeating the monsters while getting the gold.
I see this contrast, between Basic and Expert - dungeon crawling compared to wilderness exploration - as raising the same question as this thread: what is world building
for once we're no longer playing a dungeon crawling, puzzle-solving game?
Without worldbuilding you have no wilderness to explore, nor seas to sail across, nor kingdoms to live in or to overthrow. You have no history, no deities (which kinda screws over any Clerics in the game!), no moons or weather or cities or kings. You have no raiding Vikings to the north, no cultured Romans, no desert marauders, no pleasant Hobbit-filled valleys, no Elven woods.
All you have is...nothing.
Lan-"and worst of all you have no monsters to kill so you can take their stuff"-efan