On the role of physics in RPG resolution - here is a passage from Maelstrom Storytelling (p 116):
Literal vs Conceptual
A good way to run the Hubris Engine is to use "scene ideas" to convey the scene, instead of literalisms. The scene idea is the scene concept, as imagined in the mind of the narrator [= GM], whereas that might be different from the literal elements of the description when the scene is presented. A ten foot fence might seem really toall to one person, and a little tall to another. But if the fence is described as really tall instead of 10 feet, evenone gets the idea. In other words, focus on the intent behind the scene and not on how big or how far things might be. If the difficulty of the task at hand (such as jumping across a chasm in a cave) is explained in terms of difficulty, it doesn't matter how far across the actual chasm spans. In a movie, for instance, the camera zooms or pans to emphasize the danger or emotional reaction to the scene, and in so doing it manipulates the real distance of a chasm to suit the mood or "feel" of the moment. It is then no longer about how far across the character has to jump, but how hard the feat is for the character. In this way, the presentation of each element of the scene focuses on the difficulty of the obstacle, not on laws of physics. It is the idea of how hard it is, not the actual measurement of the obstacle that is important. Everyone understands adjectives such as easy, hard, and impossible, but a wide range of argument can arise from saying that the chasm is 15 feet across. By supplying the difficult of the task, the player fills in the distance relative to the character's capabilities. . . . If the players enjoy the challenge of figuring out how high and far someone can jump, they should be allowed the pleasure of doing so - as long as it doesn't interfere with the narrative flow and enjoyment of the game.
The scene should be presented therefore in terms relative to the character's abilities ... Players who want to climb onto your coffee table and jump across your living room to prove that their character could jump over the chasm have probably missed the whole point of the story.
Notice that this advice can generalise beyond jumping a chasm. It might apply to a trek. Or a climb. Or cleaning the Augean stables. Or even beating a giant in combat.
Notice also that it depends on adopting certain techniques in framing: as the game author says,
the scene needs to be presented relative to the character's abilities. This is applicable obviously in the game this text is quoted from; to Cortex+ Heroic; to HeroWars/Quest; to 4e D&D skill challenges (less so to 4e D&D combat); to Prince Valiant (within some broad limits); to Burning Wheel (again within some limits).
It is not applicable to dungeon exploration of the sort that Gygax and Moldvay describe (but is broadly applicable, mediated via the hit point mechanic, to combat in those games). It is not applicable to RuneQuest. It is not applicable to Rolemaster, neither in the case of jumping (which is resolved by reference to the distance jumped) nor more broadly (all action resolution in RM is meant to be built out of details of the gameworld, not vice versa).
It's applicability to a system like Classic Traveller is interesting. Traveller presents itself as a system like RQ or RM, and so one might think the Maelstrom advice is not applicable. But it's not as simple as that. Relatively little action resolution in Traveller involves known and measurable quantities like jumping chasms, climbing walls or digging and shovelling. How hard is it to use or adapt a Traveller-style communicator to jam another communicator's signal? What processes are involved in doing so? Who knows?! So in practice a difficulty is set (I tend to default to 8+ for
seems feasible for a trained person and 10+ for
sounds a bit tricky even for a trained person) and skill mods are added, and the play ends up being much closer to Maelstrom than one might expect.
In a game played using the Maelstrom approach, should the GM's notes include the appropriate adjectives? There are different approaches. HeroQuest revised answers "no" and instead has a chart to be used check-by-check to set difficulties; this is intended to reliably guarantee dramatically satisfactory pacing. Cortex+ Heroic also answers "no" because the difficulties are set, or at least heavily influenced by, the fluctuating state of the Doom Pool. Prince Valiant and Burning Wheel on the other hand come closer to using "objective" difficulties which can make notes in advance more applicable - though too much prep of framing might start to conflict with other priorities for those games.