Old discussion, ho! For Science!
Also note that agrav must by necessity not cancel the effects of the planet's gravitational field, as the planet is moving at incredibly high velocity in orbit. The Earth orbits at ~30km/s; as a similar rocky planet in the Goldilocks zone, Arraxis (or whatever) can be construed to have a similar orbital velocity. Cancelling the influence of the planet's gravitational field on the tank altogether wouldn't mean that it could fly, it would mean that it would be ripped from the surface and hurled into space.
Eh, there's nothing about gravity, or the loss of it, that would affect how you move relative to the planet's rotation. It's not a gravitational field constantly acting on that keeps you in place, it's simply momentum- an object in motion stay's in motion. You were born going at 30km/s and you'll stay at that speed unless a force acts on you to change that. Even without gravity, even without atmosphere. If the opposite were true, then an astronaut stepping out of a shuttle moving through space at high speeds would appear the fly behind the shuttle. This would of course mean his speed is changing, as if a force acted on him.
That said, the way the Magrider behaves suggests it does exert a force against the ground, rather than simply negating gravity, since it falls straight to within a certain distance of the ground when it is in the air. Scythes probably work on a similar principle. When a Scythe is not level, in moves in the direction in which it is tilted, and loses altitude, suggesting it exerts force downward (if it
negated gravity, its orientation would not matter). Since it does so without respect to terrain, presumably a Scythe is light and powerful enough to do this against the atmosphere itself. After all, we never see a Scythe in space, and it shares an altitude ceiling with the other aircraft which all appear to use conventional jets.
It's significantly advanced alien technology, and thus akin to magic... stop trying to explain it.
(Disclaimer: This only applies to in game and most otherwise fictional things. I fully support trying to explain any actual real world phenomena, similar to this or otherwise.)
Seconded. If tech in games could be easily explained with science, then we'd have that tech in the real world. If we knew exactly what properties affected anti-gravity tech, and what we'd need to have it, someone would've thrown money at it to make it real.
Oh, poo to that! If we treat the antigravity itself as a black box (electricity goes in, gravitational force comes out, and we don't know why) the rest is scientifically sound. Now, WHY analyze it? It's in our nature!