Does the jump spell enable you to jump down of a bridge without taking falling damage? Eg I am on a 30’ high bridge and jump off down to the ground below?

if I jump 30’ up to touch the ceiling without grabbing it do I then take 30’ falling damage when I come back down?  If I jump 15’ to touch the ceiling does the 15’ up plus 15’ down count as a 30’ jump?

Quote from Lyandriel >>

Does the jump spell enable you to jump down of a bridge without taking falling damage? Eg I am on a 30’ high bridge and jump off down to the ground below?

if I jump 30’ up to touch the ceiling without grabbing it do I then take 30’ falling damage when I come back down?  If I jump 15’ to touch the ceiling does the 15’ up plus 15’ down count as a 30’ jump?

No, this spell has no effect on falling damage. This spell just decreases the amount of movement you need to spend to jump a certain distance. If it reduced falling damage in some way, it would say that.

The spell Feather Fall is the main magical way of reducing falling damage.

If you jump 30 feet up without grabbing it, then you fall 30 feet down. You'd take 3d6 bludgeoning damage when you hit the ground.

Jumping 15 feet to the ceiling is a 15-foot jump. You can't jump down off the ceiling, because that's not what jumping is.

Quote from Unclevertitle >>

Further, nothing in the rules for jumping prevents using a Fly speed or a Swim speed for the 10 foot movement to spend for the 30 foot jump.

So let's say a creature under the effects of Jump has Gaseous Form cast on them. That creature, who's "only method of movement is a Fly Speed of 10 feet" could then use that 10 ft to jump and effectively move 30 feet per round even as a gaseous cloud.

 You say that like it's not the funniest thing.

Does this work with monks using step of the wind, which doubles your jump distance for a turn? 

Quote from Worthlesspleb >>

Does this work with monks using step of the wind, which doubles your jump distance for a turn? 

I don't see why not.

So I've put a thread in the rules discussion: https://www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/220289-jump-spell-and-distance#c2 

But how does this spell work with the Glossary rules for jumping which state that when you jump, each 1ft you jump costs 1ft of your movement? The spell doesn't explicity say that it replaces the normal jump rules. I imply from it that the lets you reach a 20ft jump distance without the need for your Str to be 20.