# What is the maximum achievable height of a creature self-concentrating under the spell Fly?

How high can someone go using only one (1) fly spell? No other means of movement or ways to change your position are allowed besides movement under fly. Assume a level 20 character with all stats at 20, plus any relevant bonuses, as well as limitless preparation time prior to lift-off. No magic items allowed. Outside assistance is permitted, but reliance on chance (such as needing a specific result on the Wild Magic Surge table) is not. Also, spells such as Dimension Door and Teleport that allow you to obtain altitude without flying and techniques to "move without movement" are not allowed, as I am asking for aviation with Fly.

Get creative! I love seeing wild shenanigans to reach arbitrary theoretical maximums!

Related for anyone concerned with the minimum height you fly with the Fly spell: How high off the ground can you fly with the Fly spell?

## Assuming you have enough height: 166,100 ft ≈ 31.46 miles

The first thing to recognize is that fly grants the creature's bonuses to its speed will also apply to this flying speed (as long as it isn't specific to walking speed). In no particular order:

• Sorcerer 11 (for Extended spell and spell slots seen later)
• Borrowed Transmuter's Stone (10 ft)
• Barbarian 5's Fast Movement (10 ft)
• Monk 3 (10 ft)
• Longstrider (10 ft)
• Mobile feat (10 ft)

We then want friends to cast expeditious retreat, and fly (both Extended). We will spend our spell slots and concentration on Extended haste's (since it only lasts 2 minutes will need to recast it a few times).

By using our normal, bonus, and haste action each turn to Dash, we'll move four times our speed each turn. However, we'll have haste ending and the lethargy + recasting costs us 5 moves (one turn's and the action to recast) for the nine times will have to do it (before fly elapses). Oh, and haste doubles our speed. So we'll get to move $$(60+10+10+10+10+10)\text{ ft.}\times2\times(4\times20\times10-5\times9) = 166100 \text{ ft.} \approx 31.46 \text{ miles}$$

• Thank you for actually giving an answer. Now that I have changed the question, perhaps you have even better shenanigans to reach for the stars? Dec 1, 2022 at 17:26
• As long as you're in sight/hearing range, you could have a Battlemaster using Maneuvering Attack to give you a half-move as a reaction. It's still using your own movement and fly speed so I think it still counts under the OP's restrictions. Dec 1, 2022 at 19:49
• @DarthPseudonym Sight range is capped at 2 miles, and hearing seems to end at around 120 ft. I don't think it changes the calculation much anyways. Dec 1, 2022 at 20:11
• Assuming no assistance from Eyes of the Eagle or whatnot, it's 2 miles, then. You should have ample time for your Battlemaster buddy to use his entire supply of 6 maneuvers for a half-move each time, or three additional move actions at a speed of 220, for a total of +660 feet. It's not nothin'. Dec 1, 2022 at 21:04
• Even if sight range is capped, you could always have a second group pull the same kind of shenanigans, or even just use teleportation magic, to keep the Battlemaster in sight/hearing range. Dec 2, 2022 at 7:04