"No, you can't do it via vaulting, you need to Jump or Climb" is probably the answer then (based on the previous discussion).
Yeah. Since just walking to the top of the ladder was shorter than the full movement value of the model, move + smoke wasn't possible, and move + shoot wasn't possible, so legal move would have been jump or climb to the top and eat a shotgun.
Was the Datz in B2B with the wall? If so then yes, you'd be correct in all interpretations. If not then it depends on how you understand the rules for Impetuous pathing to function. See this thread https://forum.corvusbelli.com/threads/jump-super-jump-impetuous.3532/page-2 But let's not discuss that here and instead merely agree that the answer is challenged by segments of the community. @Hecaton: you're discussing the debate around whether you need to measure the horizontal movement at the top of a climb or whether you get the translation from vertical to horizontal for free, right? Ie. This one: https://forum.corvusbelli.com/index.php?threads/22873/
Ok. Then it doesn't apply to ladders: on ladders you need to measure the horizontal distance. You're moving not climbing, so the incongruence between the Climbing rules and the image doesn't come up. The ladders image only shows SIL orientation, not distance
How do you measure distance when the silhouette changes orientation, as in when moving up a ladder and then transitioning to the rooftop?
I just use the base size myself. As you would either need to walk completely off the ladder (base size vert) or move forward the base size (horiz) on the roof it would balance out
The way I always understood it is that there are two surface orientations in Infinity: Horizontal and Vertical. Everything 'counts as' or is 'treated as' either one of those in various circumstances. A ladder, for example, is a vertical surface that you can move over as if it was Horizontal, i.e. you do not need to use the Climb skill. But it is still a Vertical surface. You simply treat it AS a Horizontal surface for the purposes of movement. When transitioning between a Horizontal surface and a Vertical surface, the model's entire base immediately 'snaps' onto the new surface orientation when it reaches the transition point, and this does not count as movement. For example, if a model moves 2" to the top of a vertical surface it is immediately placed on the horizontal surface with its base fully supported. The model may then continue to move, if able. This effectively grants 'additional' movement to models transitioning between vertical and horizontal surfaces, as the width of the model's base is not counted as movement along the new surface orientation. It does, however, keep movement very clean when transitioning between vertical and horizontal surfaces. Assuming this is how the rules are supposed to work, a parapet poses no conundrum whatsoever. A model would move to where its base touches the top of the parapet's outer vertical surface, immediately 'snap' to the horizontal top edge of the parapet, immediately 'snap' to the vertical reverse side of the parapet (assuming the parapet is not wider than the model's base), and finally (assuming the parapet is not taller than the model's base) immediately 'snap' to the horizontal surface of the roof. In other words, the model is immediately placed onto the roof in base contact with the parapet. Simple, direct, no muss, no fuss. You reach the top of the parapet, you are immediately placed onto the roof, in base contact with the parapet along the line of your movement path, with your base fully supported on the roof. If the model cannot do that, for whatever reason, it must simply stop moving a token 1mm away from the top of the parapet. Otherwise it would end up in a position it could not occupy. If the rules work this way, it also makes moving models incredibly straightforward. Move the model to the point of transition, place the model, move it to the next point of transition, place the model, etc. etc. I honestly do not see what all of the fuss is about, other than folks thinking it is 'unfair' for models to get 'free' movement when transitioning between surfaces. Treating a parapet like an obstacle is nonsensical. It is contiguous with the surface along which the model is moving. How does that equate to an obstacle?
It's not a question of fair or unfair, it's a question of rules intent. The text and the diagram for how to deal with Climbing disagrees. This means that the free translation from vertical to horizontal is: A) specifically tied to the rules for Climb rather than the general movement rules. B) not clearly RAI or RAW one way or the other. I'd recommend starting a new thread on it though. It's not really part of the rules for Ladders.