[3.5] How would low/high gravity affect magical flight?

[Professor Chimp]

For context, as a DM, I like building dungeons around a gimmick and then finding as many ways as possible to turn that gimmick into interesting encounters. The one I'm creating now is going to have areas with low and high gravity.

There's rules for low-high gravity in the Planer Traits but those mostly seem to account for attack rolls, skill checks and such, but not really anything on how it would affect their movement speeds, save for how the reduced/increased item weight could put characters below or above certain carrying capacity thresholds. D20 Future's gravity rules give non-native or untrained a 5ft movement penalty to account for the physical difficulties of moving in an environment where they'd be much heavier or lighter than they're used to. I'm probably going to adopt that.

But several PCs have access to some form of magical flight and that is not really dependent on a character's own physical abilities. So I'm wondering if I should let the penalty apply too, or leave it so the players have a way of circumventing it.

Of course, if anyone has a better idea, I'm all for it.

EDIT: whoops, didn't notice I posted this in the wrong section. Mea culpa.

[Segev]

I'd just have it impact them by changing their encumbrance, as with any form of movement. Particularly for magical flight, how you stay aloft against gravity is hard to state. For non-magical flight, it might make sense for it to interfere, but it's probably too much effort to justify beyond the encumbrance rules.

At most, you might make climbing cost 3x movement rather than just 2x movement.

[arch-fiend]

i think it depends on how the magical flight works. this will require some work by you as the dm to determine when they use it. horizontal speed would be unchanged so long as the flier can still manage to fly. if their magic flying is granted through gaining wings of some kind their ability to gain vertical lift speed should be halved or doubled proportional to the difference of gravity compared to their native gravity while their speed while falling is inversely affected. the weight the flight can carry is also effected by gravity in the same way that vertical lift is. if the flier has a limit for how long they can stay airborne because of endurance then it is halved in a higher gravity and doubled in a lighter gravity. onto other forms of flight, any flight which is achieved through pushing air downwards while magical or otherwise is affected the same as winged flight as is any flight which comes from a force lifting an object if that force has a limit of weight it can lift, however these are not likely to have any limits of endurance. lastly any magical flight which is achieved through some ambiguous way which is not one of the before mentioned is probably not effect by the gravity the players are in be it light or heavy.

[ArgentumRegio]

Most of the spells of that nature specify how much weight the spell can effect. In a higher gravity, the amount of weight would be reduced. the opposite for low gravity.