Can you jump farther than your movement when using magic i.e spell Jump & boots of striding and springing?
@mikemearls @Plaguescarredi’d rule yes – design intent is to make you jump super far To be clear, things like the jump spell don’t increase speed. You can jump crazy far, but your speed caps it.
— Jeremy Crawford (@JeremyECrawford) September 17, 2014
@Plaguescarred @mikemearlsAre you saying you can’t jump farther than your speed even with Jump spell or Boots of Striding and Springing? Every foot jumped costs movement, so you can jump farther than your current speed if you take the Dash action.
— Jeremy Crawford (@JeremyECrawford) September 18, 2014
So, you can jump 60 ft. if you use the Dash action?
Yes and no. With a hard cap of 20 Str, you can do long jump after a 10 ft. running start equal to your str score, so tripled with the Jump spell or Boots of Striding and Springing would make it 60 but minus 10 for that running start. Some things allow you to do a long jump without the need for a running start, THEN you could jump the full 60 ft. (the Athlete feat only reduces that running start by 5 ft. sadly)
Let’s get sillier though, the effects of the Jump spell and the Boots can stack (because it doesn’t say you’re under the effect of the Jump spell), so you can triple your jump distance to 60 with the boots, then triple it again with the spell to 180 ft. If you’re a level 20 monk, you get +30 ft of movement naturally, so if you’re a race with 30 movement initially, you by default have 60 ft of movement, so dashing gives you 120 ft., meaning you can dash jump for 120 ft., add in the Mobile feat for 10 more ft. (70 -> 140), the Longstrider spell for 10 more ft. (80 -> 160) and finally, be a wood elf for 5 more ft. and you get a grand total of 85 ft. with a 170 ft. dash possible jump (but you’d need 20 str as a monk). Insane. Of course, being a monk then means you can add Step of the Wind, which doubles your potential Jump length to a whopping 360 ft.
Now, what Jeremy doesn’t mention is that the Athletics skill mentions making jumps beyond your normal limits essentially. This means you can absolutely ask your DM to try jumping further than your movement, and there’s no rules set to the DC, so it’s up to them how to proceed. Nat 20 superman jump? Why not? I’d love to have a player willingly split themselves from the party by nigh unreachable margin. My current DM would probably just kill me from the insane amount of g-force I’d have to be experiencing from moving that distance in 6 seconds though. 😛
(Also remember that a long jump is different from a high jump, all of that math is changed to your str modifier + 3, so 8 at 20, bringing it to a potential of 144 ft. high, and also you still take fall damage.)