Ratskinner and @
pemerton, just a few more thoughts to hopefully clarify (pemerton has my position correct - I find DW's cognitive workload to be extremely minimal, and intuitive, relative to a game like 5e). I would say that I'm puzzled by people trying to shoehorn DD (Dex) into solely the few small words that are given in the descrption (...by getting out of the way or acting fast...), but I suppose I shouldn't be as folks can find a way to argue about virtually anything on games. I think the lines of evidence that support Dex as the applicable attribute and Defy Danger as the applicable default move for "skulking in shadows or from obstruction to obstruction" are infinitely stronger than any other school of thought. However, if that isn't sufficient, as chaochou has noted, you could easily write up a Stealth move (that would use...drum roll...Dex) if you feel so inclined.
On cognitive requirements and process:
What I meant to convey was that Dungeon World's conflict resolution and 4e's Skill Challenges are very much kindred spirits. What's more, the procedure for escalation of events by the GM is similar to MHRP's (with 1s rolled and the deployment of gained dice from the doom pool being the analogue to failures accrued and attendant dramatic momentum in a SC or soft moves for 7-9 and hard moves from a 6-) You've got specific components that are meant to observed: the mechanical framework/resolution scheme, player action declarations + the deployed moves/resources that accompany them, and the GM principles that bind and guide a GM's response. The triggers and keywords of the game tech all focus on (a) the immediate fictional situation and (b) an abstract response to it until the situation resolves itself (both mechanically and fictionally).
Conversely, on the cognitive requirements and process of running and playing a game like 5e, there are parts that intersect that are extremely specific and crunchy (such as concealment and how light/objects interface with it, movement rates, action economy, etc) and then squishier/vague areas that must be interpreted (such as how does this PC ability or that item interface with, or allow for bypassing of, this codified and specific part?). You can't just focus on the fiction and your GMing principles/agenda almost exclusively, let the conflict resolution chassis do the heavy lifting of adjudication, and just let the game snowball from those play procedures.
For some, the cognitive processes that underwrite the 5e/AD&D kind of gaming experience is a feature (described as liberating or GM empowering). The GM gets to play his heavy role in rules adjudication and play outcomes and the players get to deploy their crunchy bits and bobs and try to defeat the GM's challenges (and sometimes his reasoning for a ruling!). For others, they are not a feature and something more akin to the fiction-first, abstract conflict resolution model of DW, 4e SCs, MHRP (or DitV), and its attedant mental overhead and involved cognitive processes, is more to their liking. But the two are very different from one another. Hence the cognitive dissonance suffered when one plays 4e/DW/MHRP with the expectations and mental framework that is predisposed towards the 5e/AD&D model, or vice versa.
On the resolution of a stealth conflict in DW:
I was assuming that "stealth" was referring to the genre trope of "slinking along in a hallway/alley/forest, moving from shadow to shadow/obstruction to obstruction, in attempt to evade detection by sentinels, bystanders, or pursuit." The imminent danger being "detection by sentinels, bystanders, or pursuit (and whatever trouble comes with that)." In an exciting stealth conflict, this won't be the only bit of trouble/adversity that one has to deal with and it won't be the only approach. However, that is the default scenario that comes to mind (for me) when someone invokes "stealth."
If there is no "imminent danger", then you're effectively "saying yes" to a player's action declaration to be stealthy. As such, no dice are being rolled...no conflict is being resolved. You can extend that conflict-neutral scene for as long as you'd like, but as soon as there is conflict to be resolved or some form of antagonism, "imminent danger", interposes itself between the PC and his/her goal (swiping a Macguffin, infiltration or exfiltration of a protected structure), then the resolution mechanics are consulted, dice are rolled, danger is defied (or not), and something interesting happens as a result.
Regarding there being multiple types of stealth conflict and multiple ways to deal with them, I don't think many folks (if any) would disagree with that. Some quick and dirty examples off the top of my head:
* Perhaps the stealthy infiltration requires the climb of a huge wall. The player is certainly going to be Defying Danger there, but they'll be using Strength rather than Dexterity.
* Perhaps the PCs hear some guards coming down the hall and they're trapped in a room. They look around (Discern Realities) for a place to hide or something that is useful to them. They find some tunics and helms hanging on the wall; the garb of the soldiers that patrol the keep. They attempt to Defy Danger, (Int) with quick thinking, as they throw the gear on and do the Han/Luke thing, portraying themselves as keep soldiers when they deal with the imminent danger of the guards coming into the room.
In DW (just like in 4e and other conflict resolution games), any good infil/exfil conflict may involve all manner of subterfuge, skulking, and skulldugery. But the scenes that require the dice to be consulted for outcome are the ones where (1) some form of legitimate antagonism prevents the PCs from achieving their sought end and (2) something interesting will come out of the two agendas/forces colliding. In those cases, I'm either using Defy Danger (Dex) to skulk quietly from shadow to shadow/obstruction to obstruction or I would quickly generate a world move (perhaps with earned hold to spend on generating or denying a few varying outcomes) to find out what happens when. Most of the time, Defy Danger (Dex) will do the job just fine.
