Can you try it again if you get 7-9 to get another question? If you just fail, can you try again? In d20, this would be why there's the Take 20 rule. Or there's Burning Wheel's Let It Ride rule for a different approach. But neither of those really helps me figure out what the appropriate hard moves might be.
As far as I'm concerned,
there are no rerolls in Dungeon World. The whole idea here is that there is a
consequence for failed rolls, that's what it means to "make a hard move." If a player is just rolling over and over again from a safe point, there's no consequence so the dice shouldn't come out. That's really cheesing the system and I don't like it in any game.
All the talk about "hard moves" and "soft moves" and whatnot can sometimes make it more confusing than it is:
when a player fails a roll, you are telling them the consequences of that failure. That's all it means to "make a move." People get caught up choosing something from the list, but really you just gotta come up with a consequence for failure, and the list is good for helping with that.
The Moves are, more or less, just a list of options you have that can be applied in any game. They're very good basic advice for DMing.
You figure out what applies to the moment at hand, and use it.Failing a Spout Lore doesn't make a monster
attack, per se. You want your Move to flow from the fiction, so make it something related.
Think of the consequences that might arise from the failed roll and then make those consequences happen. It's honestly no different than most other games, they've just codified it and laid it out in the rules.
Edit: for example,
Discern Realities. This isn't really a "Perception Check," they don't need to roll it every time they want to ask about their surroundings. Just let them ask away and give out the details. The list of questions are for hidden info, and it says "a situation or a person." Not a room, a
situation. That means you have described something with the potential for danger: a trapped room, now that's a
situation. Then, if they fail a roll, while they're poking around the trap could go off. Or the hiding enemy jumps out. Read the description for Discern Realities, and you'll see that it shouldn't really come out unless there are
consequences. If there's really no Move you feel like you could make, consider a few all-purpose ones:
*Reveal an unwelcome truth ("we're not alone!")
*Show signs of an approaching threat ("while you're looking around...")
*Use up their resources ("researching cost you money..."
The same thing applies with
Spout Lore. You don't have to call for a Spout Lore every time they need world information. It's really when there's a chance they might not know it. And on a failure, you can Reveal an Unwelcome Truth. That's a good Move for Spouting Lore; it's not like they can roll and roll again until they succeed and "know" some facts. It's like, "You failed the roll? Well it turns out that Ogres subsist mainly on halfling flesh, that's a bummer for you, huh?"