(or, Oops, I’m Flying)
Last updated: 190505
I’ve previously calculated long-distance movement and flight, but sometimes interaction is more immediate. An issue I’ve bumped into over the years is the (grounded) PCs interacting with flying creatures. When PCs have used the Fly spell, it’s rarely been for combat. The DMG defines most aerial combat as, “a swoop and slash, hit-and-run affair.” The DMG then defines maneuverability without detailing melee combat for creatures in flight. It’s been obvious that flying creatures could attack while flying, and clearly combat doesn’t happen at Initiative (because the creature’s location would rarely line up). But how complicated is it?
If using a hex map, for simplicity, each 3” of speed equals one hex of movement. Creatures can split their turn ability across multiple hexes. But how far and fast do creatures typically go? The DMG specifies movement by class, which defines a creature’s movement rate and turn radius:
- Class A (180°) creatures reach full movement in one segment. Effectively, they have full movement each round in any direction.
- Class B (120°) creatures require six segments to reach full speed. That translates to roughly three-quarters normal movement in the first round. Class B also require 5 segments to come to a full stop—half movement in a round before a hover. Class B creatures can also remain airborne at less than half-speed. The Fly spell is class B, but specifically permits full vertical as half normal rate.
- Class C (90°) creatures require a full round to reach full airspeed, translating to half-movement in the first round. For Class C, half-speed is also the minimum to maintain flight. Class C also can’t hover. Exception: The magic carpet is class C as pertaining to maneuverability, but can hover or move at any desired speed. Much like the Fly spell, spell-casting is possible from a magic carpet if hovering or moving slowly (3” or less).
- Class D (60°) creatures require two full rounds to reach full airspeed, or a quarter movement in the first round, and half movement in the second round.
- Class E (30°) creatures require four rounds to reach full speed: 1” the first round, a quarter movement in the second round, half movement the third round, and three-quarters movement in the fourth round.
Flying creatures of less than Class A clearly need to plan their movement at least a round in advance!
- Most flying creatures can climb at one-half their normal movement, and dive at twice the stated movement. Climbing is typically one foot for every three feet forward for Class B and below (the Fly spell as the exception), but dive at 1:1.
- Creatures moving at half-speed turn as one class better.
- Winged creatures cannot move at less than one-half speed and remain airborne (except class A/B).
- Flying mounts are considered one maneuverability class less when mounted and/or carrying equipment.
- A creature’s base movement rate (but not class) decreases when burdened with more than a normal encumbrance.
All of those modifiers would be cumulative, but note that creatures dropped below Class E still function as Class E.
While the DMG describes aerial combat as a hit-and-run affair, standard melee and Initiative rules don’t work. PCs can normally move, or attack, or charge (where charge has implications for AC, To Hit, and Movement Rate). In the BtB combat sequence, actions are, in order:
- discharge missiles or magical attacks
- close to striking range or charge
- strike blows with weapons
How does that translate to aerial combat?
As all creatures are in motion, range attacks would occur prior to any melee attack. Dragons can choose to breathe on an approach and then pass and slash with fang or claw. Given the movement of dragons compared to the range of their breath weapon, this implies dragons can both breathe and melee attack in the same round! Manticores similarly can employ their front claws as well as flinging tail spikes.
Dragons and similar creatures with breath weapons (such as chimerae) have a slightly harder time hitting other flying creatures. For this reason, moving aerial targets of flying dragons add +2 to their saving throws.
For all missiles fired in the air, treat short range as medium (-2 to hit) and medium range as long (-5 to hit) as pertains to chance of hitting. Firing at long range will always miss.
As per dragons, the number of attacks per round allowed flying creatures is typically less than their default. The chimera can use claws or attack with one of its heads. Type 1 Demons can only slash with their rear talons. Giant eagles attack with their talons but not beak. Gargoyles will attempt to spear with their horn or slash with their claws, but never both. Harpies will either use their talons or a weapon. Griffons and hippogriffs attack with either their talons or beak. The examples continue, but that’s enough to demonstrate the basic principles.
And what of the Fly spell? Well, the Fly spell specifically takes as much concentration as walking. Combat therefore would be much like that of a walking character. Two creatures using Fly should be considered normal (grounded) movement.
Melee combat would occur whenever two creatures are within melee range of each other. Given flying creatures can close yet attack in the same round, melee combat should work similarly to charge—creatures move on Initiative, yet strike order would be by weapons length. Creatures with multiple attacks (claw/claw) would occur at the same time. Creatures with a multiple attacks per round with the same weapon (such as fighters with more than once attack per round) are likely far from their opponent by the time they would make their second attack, reflecting the similarity to those flying creatures that can use only one attack form. When making a melee pass, flying creatures wouldn’t expose themselves to a “free” attack, as the attack is part of their standard movement.
What else do we learn from all that? If a creature has a separate ranged attack, the range attack can be used on the way in. Creatures with multiple different forms of melee attack (claw & bite, for example) can use only one attack type when making a melee pass.
When diving all physical attacks inflict double damage against all targets that are not diving themselves, which includes attacks on earthbound creatures from a height of greater than 30 feet. Unless explicitly stated otherwise, dive attacks end with the flying creature on the ground.
The DMG defines calculating damage on flying creatures to determine when they fall out of the sky: 50% damage is forced to land, and 75% damage is plummeting from the sky. For feathered creatures that math is different, and can be calculated as 75% damage forces them to land, and 90% damage causes them to plummet.
For purposes of melee, a creature’s Stamina is unlikely to be relevant, although a few creatures have a Stamina less than or equal to three turns (the boobrie, pteranadon, giant pterosaur, and giant vulture)
Planes in WWII making head-on attacks sometimes died in head-on collisions. If both opponents are flying, either opponent fumbling could represent a head-on collision. Both opponents would stop moving, and plummet to the ground.
Clearly defined in the WSG, the details are included here for completeness. A character’s chance of falling while riding an airborne mount is checked at least once every three turns while he and the mount are airborne, beginning the count anew each time the mount lands and takes off. Again, this assumes that the flight is smooth and normal in all respects. If the weather is bad, or the mount is very uncooperative, or if it is abruptly changing direction and speed (such as in a combat or evasion situation), a check may be called for much more frequently – perhaps as often as once per round while the unusual conditions persist.
The base chance of a character falling from his mount is 0%. This assumes that the mount is giving its rider(s) a smooth and level flight at its full normal movement rate. The base chance is modified by any of the following factors:
- -200% Rider’s entire body (upper and lower) securely strapped
- -150% Rider’s lower body only securely strapped onto mount.
- -50% Rider has proficiency in Airborne Riding (in the appropriate category).
- +50% Rider not strapped onto mount and not holding on (hands are free or carrying something).
- -10% Rider using saddle.
- -10% Saddle equipped with stirrups.
- -02% per each point of rider’s dexterity above 12, and rider’s strength above 12 (considering 18 as maximum).
- +02% per each point of rider’s dexterity below 12, and rider’s strength below 12.
- +20% Mount is carrying more than its normal load limit.
- +20% Mount is moving faster than full normal movement rate (diving, dodging, performing combat maneuvers, etc.)
- + 10% Mount is not flying level (making sharp turns, loops, etc. Turns greater than 45°).
- +20% Mount’s demeanor is unwilling, and the creature is not charmed, subdued, or similarly influenced.
- + 20% Inclement weather (sandstorm, heavy precipitation, etc.).
- +01% per mph of wind velocity greater than 30.