[3.5] Combat involving flying creatures

[Morquard]

Ok, lets assume a player or a monster has a flyspeed with good manouverabilty, for example someone with a fly spell. That allows them to hover in the air without moving.

Now, if they say "I'm not hovering 1 foot above ground, but 10 or 15, so well above everyone else's head", does that
1) increase the distance to other squares on the map (and maybe the own?), and if so how is that calculated?
2) allow them to occupy the same space as another character, friend or enemy?
3) Make them save from melee attacks, because they're too high to be reached?

Now lets say they also have Invisibility or Greater Invisibility spell active, does that change any of those answers?

[Greenish]

1) increase the distance to other squares on the map (and maybe the own?), and if so how is that calculated?

A^2+B^2=C^2

Spoiler

Show

2) allow them to occupy the same space as another character, friend or enemy?

It's not the same space if the other creature is in the air above the other. You just have to start thinking in cubes instead of squares.

3) Make them save from melee attacks, because they're too high to be reached?

Quite obviously, yeah.

Now lets say they also have Invisibility or Greater Invisibility spell active, does that change any of those answers?

Not really. The flyer still occupies the same cube even if it's invisible.

[Mnemnosyne]

The biggest hurdle with flight (once you get to Good maneuverability and eliminate that minimum forward movement headache) is whether space is measured in 5 foot cubes or 5x5x10 foot rectangles. Remember that a lot of people that are medium size are still taller than 5 feet, so I would typically rule that a medium creature takes up a 5x5x10 foot rectangle, occupying ten feet of vertical space, not five. This counts the height necessary for say, swinging swords overhead and things like that.

Beyond that, yeah, as Greenish said.

[Xyk]

4) This reminds me of Schroedinger's cat. If you are flying and invisible, there is no way short of See Invisibility to know where you are because you don't make noise when you fly. So you must be assumed to be everywhere at once.

[Morquard]

Ok, you have a point with the height, so 5x5x10 might be the logical choice.
But does the "cube" (rectangle is not the right word either, since its a 2D figure) above count as ajacent in the sense that it can be attacked? That would make no sense unless you have a long lance. I mean thrusting your sword upwards you can reach maybe 12ft or so, btu certainly not 20.

Or maybe go with 5x5x5 cubes and treat the one directly above the character as available for attacks.

[Greenish]

The biggest hurdle with flight (once you get to Good maneuverability and eliminate that minimum forward movement headache) is whether space is measured in 5 foot cubes or 5x5x10 foot rectangles. Remember that a lot of people that are medium size are still taller than 5 feet, so I would typically rule that a medium creature takes up a 5x5x10 foot rectangle, occupying ten feet of vertical space, not five. This counts the height necessary for say, swinging swords overhead and things like that.

5x5x5 with 5' reach is sufficient. Yeah, many medium creatures might be taller than that, but for simplicity one can assume they aren't. Actual reach distances are given in Jump's skill description, but fall within the 10' (5' height + 5' reach) for medium critters.

[AslanCross]

I was so glad my players were all math and science students. As such, they all had scientific calculators and could compute the Pythagorean theorem by reflex. :P This helped a lot in terms of speed when computing distances.

[Morquard]

I know that formula too of course, but I figured it was way too logical for a D&D rule :)

[ffone]

C = A + B/2 where A>=B is a decent approximation for most DnD purposes, and the one DnD tends to use for 2D purposes (diagonal movement). If your players start trying to take advantage of the errors, or there's some highly critical situation (or you're not already using a grid), fall back to Pythagoras.

Jump skill mentions 8' vertical reach (for grabbing a ledge with their hands). Last time I DMed ground-to-air combat I did the same as the previous poster's suggestion: use 5'x5'x5' cubes and the regular reach rules, for effectively 10' vertical reach with a regular weapon, 15' with a reach weapon, and ignore the fact that Medium PHB races tend to be taller than 5'. Unless it's a flying gelatinous cube hovering exactly 5' off the ground, a little 'overlap' of occupied cubes is realistic. You might rule that Small PCs can't effectively attack things even 5' off the ground (they can probably literally reach 5', especially with a hop in place, but would be rather ineffective, and the flying enemy may actually start at 6' or 9' or so).

Lots of creatures, like dragons with their necks and tails and wings, actually stretch beyond their official occupied squares (with natural weapon reach somewhat represents). The roc is Gargantuan, 20'x20', but fluff text gives it 30' length and 70' wingspan. DMing I once summoned one into an area arguably too small to allow it to realistically fly, not noticing the fluff numbers 'til too late...luckily they have Wingover.

Another question is whether to let PCs make Jump checks and attack at the height of the jump - my current thinking is that this would be a move action, being movement and all, or possibly a 5' step if they just need to jump the one cube up, and that the falling, as always, is a free action afterwards (so it's not like a free vertical Spring Attack). With the 'higher ground' combat bonuses for the flying creature.

You might consider letting the PCs ready such an action, to deal with Flyby Attack opponents with reach, even though technically that's readying both a move and standard action. Also technically, PCs could (ab)use the movement rules to needlessly expend some movement and then jump, so they end their turn hovering in midair with a standard action readied to attack. (Although in that case the flyby attacker could just strafe higher and still use its greater reach.) Or you could rule that if the flyer is flyby-attacking with a natural weapon, the PC can ready an attack without jumping (attack the natural weapon part of the body).

Anyone have advice/thoughts on this?

[gomipile]

flying gelatinous cube

I think you've found a corollary phrase to "giant enemy crab."

[Curmudgeon]

If you are flying and invisible, there is no way short of See Invisibility to know where you are because you don't make noise when you fly.

Better brush up on your rules, because there's nothing that supports such a statement. You'll only avoid making a noticeable amount of noise if you have a superior Move Silently check while flying. There's even an example of hearing an airborne creature when it's gliding (to reduce noise) instead of flying in the Listen skill description.