Example of vertically to reach a lower surface : jumping from the 3rd floor balcony to the 2nd floor balcony. Doing so should thematically be possible. Geometrically we are talking about a parabola where you move right, right-downward, down, back left-downard, and left. In a parabola that is not mirrored on the vertical axis but on a horizontal axis. Because if we were doing a straight line down we would hit/collide with the balcony floor. And obviously jumping vertical to a lower surface should be possible by the rule (and they are writing specifically vertical, not diagonal, as diagonal is also listed separately).
I don't think that's fully accurate. When Jumping, measure the horizontal, vertical, diagonal or parabolic distance between the starting location and the landing spot.
The "or" there could mean a lot of things. Is the distance broken up into discrete chunks that can be vertical, diagonal, horizontal, or parabolic? The examples imply yes.
I read it as "measure the straight line (or parabolic) distance from the starting point to ending point", which means that you can only move in a straight line or a parabola. Ignoring the confusion of how you jump "straight down" from a ledge onto the ground, the examples don't seem to particularly imply any course changes during the jump. And I feel like the way climb works has a lot of those same issues, and have gotten into plenty of discussions with people about whether or not you have to subtract the width of your base from the height of a wall you can climb. In any case, I agree that the jump/climb rules could be a lot more precise, but I don't think there's any support for course changes in the air.
@toadchild There's gotta be, if people are jumping straight down from a ledge, and the wording doesn't exclude it.
It is probably the same thing as climb where the examples only work if you do not measure the horizontal movement at all and just put the base down and be done with it. Even though the rules clearly do not allow it.