The most important issue in RPG play, which these threads turn on, is who has authority over what bits of the fiction and what rules and principles govern their use of that authority.
There is a difference between Participant A having authority, and using it in accordance with a principle of consultation, taking suggestions, etc, from Participant B; and Participant B having authority.
Look at @Manbearcat's Spout Lore example. Who decides where the Forge is? What conditions govern its use? Etc? The GM:
Here, again, is Spout Lore:
Suppose they roll a 10+. The GM has to say something relevantly interesting and useful. @Manbearcat has given one example. Here's another that I just made up:
Now would the story about Vessuk be as apt a response, for the GM, as @Manbearcat's? I suspect typically not, but there might be some context where the answer is yes: eg if the Wizard is Neutral (Discover something about a magical mystery) and has a bond with the Dwarf PC that the latter is keeping an important secret from me (I'm referring here to pp 147-48 of my DW PDF).
What are the constraints on the GM? The information they provide has to pertain to the subject in question (dwarven forges) and be relevantly useful (in this case, that means useful for repairing the paladin's ruined armour). The player has established those constraints. They are not the one doing the authoring.
That's what makes it possible for the player to be surprised! It's how reveals work. While at the same time ensuring that players' goals for their PCs are likely to remain at the forefront of play.
The basic process, as I've said, is no different from GM player-authored quests: Can I have a quest to find a dwarven forge to repair the paladin's armour? - and the GM, remembering to say "yes" as often as possible, prepares the appropriate settings, encounters, treasures etc - which may involve @Manbearcat's glaciers, or my Vessuk the magic-eater, or something else that seems apt.
There is a difference between Participant A having authority, and using it in accordance with a principle of consultation, taking suggestions, etc, from Participant B; and Participant B having authority.
Look at @Manbearcat's Spout Lore example. Who decides where the Forge is? What conditions govern its use? Etc? The GM:
10+ (Interesting and Useful) - "The legend says the forge is in a dugout notched under the glacier near Camp 2. It is ever-burning so where there is meltwater, you will find the forge."
7-9 (Interesting) - "The legend says the forge is in a dugout notched under the glacier near Camp 2."
6- (Its there but here is some further suckitude to frame a decision-point as well) - "The legend says the forge is in a dugout notched under the glacier near Camp 2. The fires of the forge were quenched long, long ago...as were the lives of the dwarves who worked it. Whatever did the quenching likely still lurks within."
7-9 (Interesting) - "The legend says the forge is in a dugout notched under the glacier near Camp 2."
6- (Its there but here is some further suckitude to frame a decision-point as well) - "The legend says the forge is in a dugout notched under the glacier near Camp 2. The fires of the forge were quenched long, long ago...as were the lives of the dwarves who worked it. Whatever did the quenching likely still lurks within."
Here, again, is Spout Lore:
So consider again the player who (as their PC) declares "I believe there is an ancient dwarven forge nearby that we can use to repair the Paladin's ruined armour."Here is the Spout Lore move and some commentary on it (pp 21, 66 of my DW pdf):
Some moves . . . Give you a chance to say something about your character and their history. When you spout lore you may get asked how you know the information that the GM reveals. Take that opportunity to contribute to the game and show who your character really is. Just keep in mind the established facts and don’t contradict anything that’s already been described.
. . .
Spout Lore
When you consult your accumulated knowledge about something, roll+Int. ✴On a 10+, the GM will tell you something interesting and useful about the subject relevant to your situation. ✴On a 7–9, the GM will only tell you something interesting—it’s on you to make it useful. The GM might ask you “How do you know this?” Tell them the truth, now.
You spout lore any time you want to search your memory for knowledge or facts about something. . . .
On a miss the GM’s move will often involve the time you take thinking. Maybe you miss that goblin moving around behind you, or the tripwire across the hallway. It’s also a great chance to reveal an unwelcome truth.
Just in case it isn’t clear: the answers are always true, even if the GM had to make them up on the spot. Always say what honesty demands.
Suppose they roll a 10+. The GM has to say something relevantly interesting and useful. @Manbearcat has given one example. Here's another that I just made up:
GM (in response to 10+ roll on Spout Lore): You reflect further and recall the stories of Vessuk the magic-eater. How could Vessuk have forged so many fine weapons, other than by having absorbed the powers of the dwarven forges? You recall that Vessuk lives on the other side of the hills, and is known to do favours in exchange for new magic.
Now would the story about Vessuk be as apt a response, for the GM, as @Manbearcat's? I suspect typically not, but there might be some context where the answer is yes: eg if the Wizard is Neutral (Discover something about a magical mystery) and has a bond with the Dwarf PC that the latter is keeping an important secret from me (I'm referring here to pp 147-48 of my DW PDF).
What are the constraints on the GM? The information they provide has to pertain to the subject in question (dwarven forges) and be relevantly useful (in this case, that means useful for repairing the paladin's ruined armour). The player has established those constraints. They are not the one doing the authoring.
That's what makes it possible for the player to be surprised! It's how reveals work. While at the same time ensuring that players' goals for their PCs are likely to remain at the forefront of play.
The basic process, as I've said, is no different from GM player-authored quests: Can I have a quest to find a dwarven forge to repair the paladin's armour? - and the GM, remembering to say "yes" as often as possible, prepares the appropriate settings, encounters, treasures etc - which may involve @Manbearcat's glaciers, or my Vessuk the magic-eater, or something else that seems apt.