I thought it was a rule that a flying creature can only carry a light load aloft? At least...every flying creature that could potentially serve as a mount seems to have such text in their descriptions...
Yes, this. The owl can carry up to 6.5 pounds and still fly: 13lbs for a light load at 4 Str, halved because it's Tiny. As such, if the wizard and his gear weigh more than 52lbs before casting
reduce person, the owl can't carry him.
Also, as Vegepygmy says, do make sure you understand the rules of aerial movement and combat. Just for example, the wizard's Owl has a maneuverability rating of Average and thus has a minimum forward speed it has to maintain during a round: if it can't or doesn't move 20ft during its turn, it falls.
The Rules of the Game: All About Movement articles on the Wizards website are extremely helpful for expanding on the somewhat sketchy rules in the DMG. They cover such scenarios as mid-air grappling, striking objects, stalling, free-falling, turning (changing direction also uses movement for most creatures) and so on, as well as explicitly clarifying that creatures can only fly with a light load, as does the FAQ.
3.5 FAQ said:
You can use a fly speed only when carrying a light load or less. If your load is medium or heavy, you cannot fly; certain kinds of magical flight, such as a fly spell, don’t have this restriction. Check the description of the flying effect to be sure. A griffin or a spider-eater can carry a medium or heavy load, but it cannot fly when doing so.
You'd just as well regard these articles as definitive: it's not like there's anything much else to go by!
The easiest way to deal with the "aerial cone" problem is probably to imagine it in two dimensions, then stand it upright: you don't actually have to perform any 3D calculations at all. Think triangles. You see, despite the PHB saying "A cone-shaped spell shoots away from you in a quarter-circle in the direction you designate," I'd be inclined to simplify matters a little. I do, in fact, on the grounds that the PHB's description is self-contradictory.
If you draw it as a quarter-
circle in two dimensions, the result isn't a cone when translated into 3D: a cone has a flat base by definition, and as such would look like a triangle when viewed from above in 2D. So I just draw it as a right-angled triangle of a height equal to the listed range of the cone. The maths get
much easier then because you're not having to calculate arcs any more. The answer to any question of whether or not someone's in the area of effect can be answered with a calculation involving nothing more complex than a right-angled triangle.
The width of a D&D cone-shaped burst (if you accept it terminating flat rather than curved) is equal to twice the range: a 60ft cone, for instance, terminates in a circle of 60ft radius or 120ft diameter. At half the distance, it's half the diameter, and so on. Easy. Well, easi
er, at any rate
I mean, by all means keep the PHB non-cone-shaped-cone-shaped burst if you prefer, but be prepared to exercise your geometry skills as a consequence.
