Making a task harder is not actually different from making a situation harder, since Dungeon World is situation-based, not task-based. That means your options as GM are the same:
- Point out that there is a Danger involved in the more difficult task, and ask how they mitigate that danger. If they try to mitigate it, they will trigger a Defy Danger move.
- Make the consequences of the potential failure heavier.
Those are your options. To be clear, this is not an option without changing the rules of the game:
- Add a difficulty modifier to the roll.
The book goes into detail why not in the Advanced Delving chapter under “Changing the Basics”, on page 355 (PDF pagination), because yeah, trying to add task difficulty to the game is messing with the basic structure of the game:
Another basic that’s occasionally asked for is a way to make, say, fighting a dragon harder. The best answer here is that fighting a dragon is harder because the dragon is fictionally stronger. Just stabbing a dragon with a normal blade isn’t hack and slash because a typical blade can’t hurt it. If, however, that isn’t enough, consider this move from Vincent Baker, originally from Apocalypse World (reworded slightly to match Dungeon World rules):
When a player makes a move and the GM judges it especially difficult, the player takes -1 to the roll. When a player’s character makes a move and the GM judges it clearly beyond them, the player takes -2 to the roll.
The problem with this move is that the move no longer reflects anything concrete. Instead, the move is a prompt for the GM to make judgment calls with no clear framework. If you find yourself writing this custom move, consider what difficulty you’re really trying to capture and make a custom move for that instead. That said, this is a valid custom move, if you feel it’s needed.
As it says, adding difficulty modifiers to the game via a move is a valid hack. But, someone contemplating adding it because they don't know how difficulty is normally handled is probably not familiar enough with the game's engine to hack on it, and shouldn't. The result of adding difficulty modifiers is a) disappointing and b) distracts from the parts of the game engine that actually make it fun as a player. Your players won't thank you for adding difficulty back into a game system that is explicitly designed to avoid the GM setting difficulties.
So let's look instead at the situation presented and the ways it's actually handled by the game engine, with the GM acting as the executor of the engine…
Difficulty is situational
The situation described is pretty bare-bones presenting some difficulties. Dungeon World's rules rely heavily on a rich fictional context, so that makes it difficult to illustrate how the game is supposed to work. I know it's supposed to be a minimal example to get at the crux of the issue, but minimal examples like that ignore basic things about how DW works. We'll need to fix it up or note the problems before being able to explain what should happen.
First, no moves would be triggered in this example. The barest extra context necessary is to say that the ogre and the human are enemies, which is required for the Volley move to trigger (“When you take aim and shoot at an enemy at range” — yes, that does mean that shooting at a non-enemy doesn't trigger Volley). So we have an enemy ogre and an enemy human.
Second, the situation is also technically impossible — between Alice shooting and Bob shooting, Alice's Volley move would trigger and change the situation in an improvised, dynamic way, making Bob's shot happen in a different context that is impossible to predict without actually playing to find out what happens. Does Alice roll a 6− and something happen, like a GM move of Separate them, meaning maybe Alice shifted her weight while aiming, triggered a trap, and suddenly Bob and Alice are hanging from snares way up in the air? Bob can't make a shot then.
So let's fix the situation and say that they're separate situations in time and space, so they're not immediately able to affect each other. At some point in the game, Alice shoots at an enemy ogre at 100 paces; at some other distant point in the game, Bob shoots at an enemy human also coincidentally at 100 paces.
Finally, robbed of actual game context, we're robbed of the ability to bring most of the game's rules to bear. There could be all kinds of things that would be relevant to a real GM running this situation in a real game that would make the question's answer more obvious, but we'll have to do without rich context. Let's just assume that the only difficulty involved is that the human is a smaller target.
Why is this harder?
Before making something harder, you have to ask yourself why it's harder, then make a GM move based on that. You can't just say, “Bob, that shot is harder”, because then you've broken the rules and you're going to have a bad time GMing the broken game that results. (Why is that breaking the rules? Well, because what GM move is that? It isn't one.)
When tempted to make something harder, there is no legal mechanism to do so. If the player has already said their PC is taking the shot and you've already all agreed that it's triggering Volley, then it's not the GM's turn to make a move and doing anything other than following the rules for the triggered move is hijacking the game to break the rules just to stop the player from benefitting from the rules of the game that are designed to let them do exactly that.
If the player isn't already taking the shot, then something else is happening. If they ask, “I'm gauging the distance; can I make this shot?” then the GM is allowed to make a move, because the trigger for GM moves happened (“when the players look at you to see what happens…”). Then you have to answer by making one of your GM moves. Still “the target is small” is not something that can come out of a GM move. The closest GM move would be tell them the consequences and ask, but “small” isn't a consequence, right? So you have to say something else.
You'd have to ask yourself things like “Why is the human being a smaller target a problem?” If the answer is just “uh, because it's marginally smaller?” then Dungeon World does not care. It's already got that taken care of: a Volley potentially involves more than one arrow, so if one misses, hey, maybe arrow number two hits. Or the third, or fourth, whatever. But if that's what happens, it's up to the player to decide that by choosing You have to take several shots, reducing your ammo by one while following the move's rules.
But maybe the answer to why it's harder is way more interesting! Maybe it's not just “well maybe you have a better chance of missing…” and it's actually somemthing way more interesting, like, “Well, the human being a hard target at this range is a Danger because if you miss they'll alert the whole army camp”, or maybe it's “…if you miss the arrows could hit the Magic Vortex and unleash who-knows-what”, or maybe it's “…if you miss then you're not going to impress the Hierarch of Love who's watching you after you boasted that you could make this in a single shot.”
Spending your energy on thinking of more interesting situations is what Dungeon World is trying to force you to do instead. Don't fight the game's attempts to make your GMing more enjoyable for the players!
How to shoot at smaller targets
So, returning to the beginning, there are two ways to make doing something more difficult in Dungeon world:
- Point out that there is a Danger involved in the more difficult task, and ask how they mitigate that danger.
- Make the consequences of the potential failure heavier.
The first is only really possible with the rich context of a real game, so if you want that, you're going to have to invent something interesting to ask the player about. The second is part of how Dungeon World's moves flow into each other and create, improvisationally, an unexpectedly rich and fantastic world without pre-planning.
But what if neither option makes sense?
Then stop trying to make the shot harder. It's not necessary and the game has way more important things for you to think about.
Besides, the 2d6 + stat method is so granular that the randomness of the roll itself is usually more significant than the tiny difficulty adjustment that you're probably imagining. Are Alice and Bob equally likely to make the shot? Maybe.
But that doesn't matter. What matters is whether they do make the shot, and that is, in the end, not the GM's job to determine or fiddle with. That's the dice's job, so let them fall where they will and play to find out what happens. Chances are, they won't both make the shot, and regardless the game will fractally change based on the moves' outcomes.
Why does Dungeon World make this so hard to do?
Because the GM arbitrarily making a player less likely to succeed at something is directly contrary to the basic design goals of the game. Dungeon World wants every difficulty to be due to the organic interaction of in-game events or circumstances which the players can attempt to grapple with (or be afraid of), instead of arbitrary GM statements. Any action on the GM's part that doesn't
- Portray a fantastic world
- Fill the characters’ lives with adventure, or
- Play to find out what happens
… is failing to deliver on the play experience that Dungeon World advertises. Making an arrow-shot harder is a waste of time when you could be using that time and mental energy to make the game more fun and the world more interesting instead.
In the final tally, this is one of the ways that Dungeon World is very different from other RPG designs, and it's common for people to second-guess it, mistrust it, or plain miss that it's part of the design. Adding modifiers is a frequent suggestion that those new to the game have, and the discussion that it prompts is always super-enlightening. Reading such discussion threads is helpful even for those who are “old hands” with Dungeon World, like myself, because all these rules are an attempt to encode and convey a method of GMing, and as we all know, there is always room to improve and better understand a given GMing style!