Dungeon World isn't D&D (or any other RPG)

It's just supposed to have a classic fantasy "feel" to it. I think everyone else covered things pretty well, but I think the critical thing you're missing in thinking about this is that Dungeon World rather explicitly wants failure to be interesting. Not only is that when GM moves happen, but it's also when you gain XP. Everything is tied into this idea of story, then roll, then story; which means that by adding circumstance modifiers you're actually messing with the whole system.

It's also worth noting that if the narrative suggests something should be impossible (Volleying a target through a solid wall, Hack and Slashing toe-to-to with a Tarrasque, or Defying Danger through an army focused entirely on you to reach the general) you just can't do it. This shouldn't come up often, but when it does it's critical to remember this rule. Likewise if something is unlikely to fail - especially in an interesting manner - (throwing a torch into the next room, a coup de grace against a hostage, climbing a young and sturdy tree) it should just happens; no roll required.

Dungeon World isn't D&D (or any other RPG)

It's just supposed to have a classic fantasy "feel" to it. I think everyone else covered things pretty well, but I think the critical thing you're missing in thinking about this is that Dungeon World rather explicitly wants failure to be interesting. Not only is that when GM moves happen, but it's also when you gain XP. Everything is tied into this idea of story, then roll, then story; which means that by adding circumstance modifiers you're actually messing with the whole system.

It's also worth noting that if the narrative suggests something should be impossible (Volleying a target through a solid wall, Hack and Slashing toe-to-toe with a Tarrasque, or Defying Danger through an army focused entirely on you to reach the general) you just can't do it. This shouldn't come up often, but when it does it's critical to remember this rule. Likewise if something is unlikely to fail - especially in an interesting manner - (throwing a torch into the next room, a coup de grace against a hostage, climbing a young and sturdy tree) it probably doesn't trigger a move in the first place; no roll required.

Dungeon World isn't D&D (or any other RPG)

It's just supposed to have a classic fantasy "feel" to it. I think everyone else covered things pretty well, but I think the critic thing you're missing in thinking about this is that Dungeon World rather explicitly wants failure to be interesting. Not only is that when GM moves happen, but it's also when you gain XP. Everything is tied into this idea of story, then roll, then story; which means that by adding circumstance modifiers you're actually messing with the whole system.

It's also worth noting that if the narrative suggests something should be impossible (Volleying a target through a solid wall, Hack and Slashing toe-to-to with a Tarrasque, or Defying Danger through an army focused entirely on you to reach the general) you just can't do it. This shouldn't come up often, but when it does it's critical to remember this rule. Likewise is something is unlikely to fail - especially in an interesting manner - (throwing a torch into the next room, a coup de grace against a hostage, climbing a young and sturdy tree) it should just happens; no roll required.

Dungeon World isn't D&D (or any other RPG)

It's just supposed to have a classic fantasy "feel" to it. I think everyone else covered things pretty well, but I think the critical thing you're missing in thinking about this is that Dungeon World rather explicitly wants failure to be interesting. Not only is that when GM moves happen, but it's also when you gain XP. Everything is tied into this idea of story, then roll, then story; which means that by adding circumstance modifiers you're actually messing with the whole system.

It's also worth noting that if the narrative suggests something should be impossible (Volleying a target through a solid wall, Hack and Slashing toe-to-to with a Tarrasque, or Defying Danger through an army focused entirely on you to reach the general) you just can't do it. This shouldn't come up often, but when it does it's critical to remember this rule. Likewise if something is unlikely to fail - especially in an interesting manner - (throwing a torch into the next room, a coup de grace against a hostage, climbing a young and sturdy tree) it should just happens; no roll required.