Regardless of Kaelik being needlessly dickish, he has a point. It's much easier to steal rules from other areas of the game and apply them to flight than it is to invent your own flight-specific rules.
Most of the environmental hazards of combat on the ground can be replaced by the hazards of falling
to the ground when you're fighting while flying. The SRD says you fall 150 ft in the first round of falling and 300 ft every round thereafter (though confusingly enough, this is hidden away in
the section on planar travel). This means that in most circumstances, falling during aerial combat is going to drop you to the ground (doing 1d6 damage for every 10 feet you fell, to a max of 20d6 at 200 feet). This makes falling a good punishment for doing something stupid while flying -- it does damage that's not overwhelming, but isn't completely ignorable either. Also, the higher you get into the air (ie the farther away you get from the guys who can't fly), the greater that punishment is. In addition, hitting the ground gives those folks a good chance to stab you (or grab you so you can't go sailing away again, if they're smarter), which is also good. I'd rule that hitting the ground leaves you prone in the square where you landed. If you want to be especially mean, make them dazed or stunned as well (fort negates?).
I'd say allow any special attack usable on the ground to be used in the air as well. Replace "prone" with "falling" in the case of trips and overruns. A bull rush replaces the target's moved distance with the distance he was bull rushed for purposes of stalling (ie, if they were bull rushed 5', then they count as having moved 5' that turn to see if they stall or not). Grapples are resolved as on the ground, except that a pinned combatant is dead weight and must be held aloft by the one pinning him, or else both fall. "Falling" (or "plummeting" if you prefer) would mean you're in an uncontrolled decent, losing altitude as if in free fall (ie, at a rate of 150 ft the first round and 300 ft thereafter), losing your dex bonus to AC, and drawing AoOs as normal for movement. A Flight check would allow you to recover from a fall as a move action that draws an AoO. It strikes me that being AoOed while recovering from a fall should increase the Flight check's DC, but I'm not sure how exactly that should work.
Now let's take a look at the questions you posted earlier.
MGuy wrote:How are things like flight maneuvers covered?
Depends on what you mean by "maneuvers". If you mean things like trips and grapples, I already covered that. If you mean the sort of stunts you'd see at an air show (ie, more complicated movements than just "going in this direction"), a flight check with a flat DC. If you mean the sort of techniques you use to get an advantage over your opponent in a dogfight, then an opposed flight check.
MGuy wrote:What should be the DC for a barrel roll?
What does a barrel roll do? Does doing a barrel roll give you some sort of mechanical advantage? Does it just look cool? DCs should be tied to how much it helps you accomplish a specific goal. If you're just showing off, then treat it like a Perform check (as you can with Tumble or Slight of Hand checks).
MGuy wrote:What should be the damage threshold per hit before you start falling/plummeting? How does it scale for smaller/bigger creatures/objects?
I don't think you should start falling just from damage unless you're reduced to 0 or fewer HP. If you want to knock someone from the sky, then you want to trip or bull rush or overrun them.
MGuy wrote:What kind of bonuses/penalties do you get based on size?
I'd give the Flight skill bonuses for size equal to what Hide gets: that is, Fine +16, Diminutive +12, Tiny +8, Small +4, Large -4, Huge -8, Gargantuan -12, Colossal -16. Generally speaking, smaller things are going to be better at flying. A mosquito is better at flying than a hummingbird, which is better than a pigeon, which is better than an vulture.
MGuy wrote:Should fighting at different altitudes produce differing effects?
Fighting at "treetop level" (where hitting the ground if someone trips you is a real possibility) is tactically different enough from fighting in "open sky" (where you'll virtually always be able to recover before you hit the ground) that it doesn't need explicit mechanics. If you like, increase the windspeed as you go higher. When you get to a certain altitude, dealing with cold becomes an issue, and somewhere above that so does suffocation. Both can be dealt with
as indicated by the SRD.
MGuy wrote:What about dogfights? Do windy conditions fuck up your flying checks?
Dogfighting as we know it is an outgrowth of the physics of the fixed-wing aircraft, and doesn't apply very well to high-level combat in D&D, where PCs would be more like helicopters (with precise control over their position) than fighter jets (who have to keep moving forward to avoid crashing). Dogfighting is probably best handled as a simple opposed flying check. But in any case, I would put the penalties to flying for wind at the same as the penalty for a listen check as noted
in the SRD; -2 at "strong winds" and doubling for every category after that (including -16 in a hurricane and -32 in a tornado, which aren't actually listed for listen checks).
MGuy wrote:What kind of advantages (bonuses/penalties) do you get for different flight maneuvers/abilities/skill checks?
I'm not sure what you're referring to here. Flight should probably use dex as its key skill, and maybe have a synergy bonus from Tumble? Other than that I don't know what you mean.
MGuy wrote:Should maneuverability be tied to bonuses?
I think maneuverability in terms of "clumsy, poor, average" etc is dumb and skill checks should replace everything that those deal with.
MGuy wrote:Should it be relegated by size/propulsion (whatever is keeping you airborne)?
I'd say not; too complicated. It doesn't matter whether you're flying because you've got wings or because of a spell; either way someone can still send you topsy-turvy in midair with a trip attack that causes you to fuck up your flying and head toward the ground at painful speeds.
