Jowgen
2018-03-22, 01:16 AM
I wanna figure out how to best set DCs for jumps that include both horizontal and vertical movement, e.g. up 10 ft as well as forward 10 ft. I think I have this figured out, but just wanted to run it by the playground.
Rules as is
Jump comes in long and high jump. A high jump is simply a jump in place to gain vertical height. A long jump lets you cover horizontal height, but you also gain altitude in the course of your jump, maxing out at the mid-point of your jump and equal to one quarter the horizontal length covered.
This corresponds to the check DCs for jump, wherein long-jump DC is equal to the distance in feet and high jump DC is equal to the height times 4. The vertical altitude gained at a long-jumps midpoint is equal to the altitude you would have gained in a long-jump at the same DC.
Tackling the issue
Now in the basic up 10 ft and forward 10 ft example, the DC to gain the altitude would be 40. Question is if and how one should adjust the DC if those 10 ft up should be combined with a 10 ft forward (like, jump onto a wall 10 ft away).
My first thought is that any high-jump ought to include some lee-way allowing concurrent horizontal movement based on the check result. On a DC 40/40 ft long-jump, we would've hit the 10 ft height at the 20 ft midpoint. So my first thought solution would be that any high-jump can have optional horizontal movement equal to half the check result.
So lets apply this and stick with a DC 40 jump check. This allows us to gain a height of 10 ft and also specify that this high point is reached in any square within 20 ft. With a DC 40 check, one could therefore jump up to 10 ft high into any square within 20 ft. Like 10 ft up, 10 ft forward. I think this part is pretty good as is.
Now if this jump takes you onto a solid surface (e.g. roof or tree top), then there is no issue, but if the designated target square is in mid air, we are faced with the issue of where the jumper should land. One might argue that the character needs to maintain a symmetrical arc, so that if they don't have a supporting surface at the high point, then they need to continue travelling in the same horizontal direction for the same length of horizontal distance covered to get up there. So we go 10 ft up and 10 ft forward, but then need to keep on going another 10 ft to touch down.
Alternative, one might argue that a jumper can adjust their momentum so that they don't have to continue in a symmetrical arc; so the jumper can choose to touch down anywhere between the high point and the projected end point, i.e. go forward and up 10 ft, then touch down 5 ft beyond that on a straight horizontal. The jump rules are a rather crude approximation of jumping physics as is, and obviously don't account for things like spin or other air acrobatics to adjust trajectory. This seems like something that might warrant a separate jump-check or an adjustment to the DC, but that seems rather redundant. Perhaps a Tumble check? Thoughts anyone?
Other considerations
How does any of this interact with movement limits per round? Vertical distance gained as a part of a long-jump doesn't count. The rules never specify whether/how high jumps interact with movement limits. Hopping up onto a waist-high surface is a DC 10 check that takes up double movement, but that is a special use that doesn't even require a running start by default. Can it be that by default only horizontal movement on the battle-grid counts? Any references to settle this would be most appreciated.
Also, jumping as a part of 5 ft steps. Depending on the above, one could potentially jump up 10 ft as part of a 5 ft step, which might be situationaly useful. Like most of this stuff. Jump IS largely useless after all. Probably not worth all this consideration to be fair, but whatevs.
Rules as is
Jump comes in long and high jump. A high jump is simply a jump in place to gain vertical height. A long jump lets you cover horizontal height, but you also gain altitude in the course of your jump, maxing out at the mid-point of your jump and equal to one quarter the horizontal length covered.
This corresponds to the check DCs for jump, wherein long-jump DC is equal to the distance in feet and high jump DC is equal to the height times 4. The vertical altitude gained at a long-jumps midpoint is equal to the altitude you would have gained in a long-jump at the same DC.
Tackling the issue
Now in the basic up 10 ft and forward 10 ft example, the DC to gain the altitude would be 40. Question is if and how one should adjust the DC if those 10 ft up should be combined with a 10 ft forward (like, jump onto a wall 10 ft away).
My first thought is that any high-jump ought to include some lee-way allowing concurrent horizontal movement based on the check result. On a DC 40/40 ft long-jump, we would've hit the 10 ft height at the 20 ft midpoint. So my first thought solution would be that any high-jump can have optional horizontal movement equal to half the check result.
So lets apply this and stick with a DC 40 jump check. This allows us to gain a height of 10 ft and also specify that this high point is reached in any square within 20 ft. With a DC 40 check, one could therefore jump up to 10 ft high into any square within 20 ft. Like 10 ft up, 10 ft forward. I think this part is pretty good as is.
Now if this jump takes you onto a solid surface (e.g. roof or tree top), then there is no issue, but if the designated target square is in mid air, we are faced with the issue of where the jumper should land. One might argue that the character needs to maintain a symmetrical arc, so that if they don't have a supporting surface at the high point, then they need to continue travelling in the same horizontal direction for the same length of horizontal distance covered to get up there. So we go 10 ft up and 10 ft forward, but then need to keep on going another 10 ft to touch down.
Alternative, one might argue that a jumper can adjust their momentum so that they don't have to continue in a symmetrical arc; so the jumper can choose to touch down anywhere between the high point and the projected end point, i.e. go forward and up 10 ft, then touch down 5 ft beyond that on a straight horizontal. The jump rules are a rather crude approximation of jumping physics as is, and obviously don't account for things like spin or other air acrobatics to adjust trajectory. This seems like something that might warrant a separate jump-check or an adjustment to the DC, but that seems rather redundant. Perhaps a Tumble check? Thoughts anyone?
Other considerations
How does any of this interact with movement limits per round? Vertical distance gained as a part of a long-jump doesn't count. The rules never specify whether/how high jumps interact with movement limits. Hopping up onto a waist-high surface is a DC 10 check that takes up double movement, but that is a special use that doesn't even require a running start by default. Can it be that by default only horizontal movement on the battle-grid counts? Any references to settle this would be most appreciated.
Also, jumping as a part of 5 ft steps. Depending on the above, one could potentially jump up 10 ft as part of a 5 ft step, which might be situationaly useful. Like most of this stuff. Jump IS largely useless after all. Probably not worth all this consideration to be fair, but whatevs.