Does a monk's Unarmored Movement speed increase apply to the fly speed gained from a Fly spell?

A monk's Unarmored Movement class feature increases the monks speed by 10 feet at level 2, and further at higher levels. According to this tweet by Jeremy Crawford, this stacks with an Aarakocra monk's fly speed, because that fly speed is innate to the race.

However, how does this interact with fly speeds gained from other sources, such as the Fly spell?

That spell specifically states that "the target gains a flying speed of 60 feet for the duration." Can this gained flying speed then be improved by a monk's Unarmored Movement, giving a level 2 monk a flying speed of 70 feet while the Fly spell is active on them?

Yes, it applies to all movements

Unarmored Movement (PHB, 78) States:

Starting at 2nd level, your speed increases by 10 feet while you are not wearing armor or wielding a shield.

It does NOT qualify as your Walking Speed (or Swimming Speed, or Flying Speed)...just Speed. This applies to all types of movements and would add additional speed to the Fly spell as well.

This is supported by Jeremy Crawford as well.

Unarmored Movement is intended to increase a monk's innate speed, including an aarakocra monk's flying speed.

He further clarifies Bonuses and Penalties that apply to Speed in general:

Bonuses/penalties to speed apply to your speeds in general, unless the text specifies walking, flying, etc

As the Unarmored Movement does not specify a specific type of speed, it applies to all.

Fly Spell specifically

Fly states (PHB, 243)

The target gains a flying speed of 60 feet for the duration.

The implication here is that you (the target) had no Fly Speed (or a lower Fly Speed) before casting and it is now a speed that you, the target have. Once it becomes your speed, it becomes subject to Unarmored Movement.

Similar to Special Types of Movement in the PHB, page 182)

While climbing or swimming, each foot of movement costs 1 extra foot (2 extra feet in difficult terrain), unless a creature has a climbing or swimming speed.

Here, Swimming has a penalty, unless they have a Swimming Speed. Once they have that Speed, from whatever source, then Unarmored Movement should apply.

Rule of Cool

And it's fun! Monks are supposed to be super quick. Let them be super quick in all their speed!

• It's the word innate in Crawford's answer that gives me pause. Is the speed from the Fly spell innate to the monk? I would argue it's not, since it's coming from the spell, not the monk itself. – A Decker Jan 18 '18 at 18:28
• Now that I see your edit, you do make a good point with the rule of cool! We tend to bend the rules slightly at my table anyway, so while I'd like to find a RAW answer, I think this one makes the most sense to me. – A Decker Jan 18 '18 at 18:43
• @ADecker You made a good point as well, but given the looseness of the language and the whopping 10 extra feet it seems silly not to allow it. – NautArch Jan 18 '18 at 18:48
• twitter.com/JeremyECrawford/status/770683371735232512 might help clarify the "innate" argument with a more general ruling but it is very clear – Rubiksmoose Jan 18 '18 at 19:33
• @NautArch: Except it's not just 10 extra feet. It's 10 extra feet at second level, rising to 30 extra feet by 18th level. I'm not disagreeing with the rest of your argument, just pointing out that a 50% increase in movement speed (for the best form of standard movement) is not de minimis. – ShadowRanger Aug 9 '19 at 15:28

I would say that in the case of the fly spell unarmored movement is not applied.

This is based on the fact that the sage advice calls out;

Unarmored movement is intended to increase a monk’s innate speed.

The speed in the case of the fly spell is not an innate flying speed as in the case of an aarakocra of a winged variant tiefling.

Also, the spell specifically calls out that it gives you a flying speed of 60 feet.

As a monk you are more in tune with your body and as such are able to move much faster when it comes to moving in ways that your body is used to moving as a result of your training in how to best use the energy of their body:

Whatever their discipline, monks are united in their ability to magically harness the energy that flows in their bodies. Whether channeled as a striking display of combat prowess or a subtler focus on defensive ability and speed... (PHB 76)

This suggests that it is the monks ability to harness the magical energy of their own body that gives the unarmored movement feature, unless the creature has an innate flying speed, it seems unlikely that the monk could use the magical energy of their body to increase a fly speed.

Having said all of this, there is something to be said for NautArch’s comment on rule of cool.

I would think fly speed would be its own speed and unaffected by Unarmored Movement. As you are using your legs to propel yourself forward and gaining fly speed from a spell or wings would no longer be your legs.

As its 9th level description;

" At 9th level you gain the ability to move along vertical surfaces and across liquids on your turn without falling during the move"

That leads me to believe that your feet need to be touching a surface to gain the benefit from Unarmored Movement.

• The Sage Advice I linked to directly contradicts this though, because Jeremy Crawford said Unarmored Movement does improve an Aarakocra's fly speed. Unarmored Movement clearly doesn't depend on legs. – A Decker Jan 18 '18 at 18:08

I think it is pretty universal that monks speed increase applies to both its foot speed and its wing speed, since both haver to do with the creatures body/muscle control doing the work. (legs muscles with foot speed wing muscles with wing speed.) the spell on the other hand is magic, magic has no real rules like that, s either call works. take feather fall for instance. it slows a persons decent down enough not to sustain damage really from a fall, but it doesn't slow it down based on the aerodynamics of the creature (which honestly might really mess with a winged creature swooping down on prey, or it just not being used to the difference. casting feather fall on a dragon effectively stops it from swooping down and wrecks havoc with its flight ability for at least a bit I would imagine.) or other things. the spell fly dos say it magically makes that flight 60 ft, not +60 to whatever it had previously.

it depends on the spell details

I believe that the monk's unarmored speed boost is about maneuvering his body with precise movements for greater movement efficiency.

As for flight.. precise movements might increase the fly speed during a fly spell by swimming or diving through the air for increased speed ..but only if air-resistance remains, as the spell doesn't explain the manipulation, only the effect..

As for the winged race "Aarakocra". An Aarakocra monk has wings allowing it to use precise movements to fly