Reverse Gravity

[SometimesCrumb]

I've got an encounter with a glabrezu coming up tomorrow and I kind of need things to be clear, for myself and my players, for when I hit them with Reverse Gravity. I have a few questions
I've got a 6 player group, 2 melee, 1 martial ranged, 1 wiz, 1 cleric, 1 bard. The Bard and Wizard can fly out of this.
are concentration checks needed for casting while in the area of effect?
can the ranged fighter still make ranged attacks as normal? How does the change in gravity affect arrows once they leave the AoE, if any? (am I overthinking this?)
because there is a roof, are the melee stuck where they 'landed' or can they theoretically re-orient themselves and walk out of the area and thus fall back to the ground?
any help is appreciated, thanks

[Kayerloth]

Let's see

1) Perhaps, a concentration check would probably be appropriate if the change in gravity occurred while they were casting or maintaining concentration on an ongoing spell. But not for simply being in the area effected by Reverse Gravity. Certainly not unreasonable to call the unexpected change as vigorous movement or similar as the GM feels is appropriate.
2) Yes though I could see a minor penalty applying for firing thru or into areas with multiple gravity directions ... something like -2 perhaps. But really that's a GM judgement call Reverse Gravity doesn't specify any particular penalty for such activity. The arrows flight path would be a bit "odd" but nothing that couldn't be dealt with. Not to unlike encountering strong winds blowing in different directions along the flight path.
3) I think they would have basically "fallen". Acrobatics or something similar to determine if they are prone, but nothing would prevent them from moving out along the ceiling and then falling, jumping or otherwise moving back to their original floor.

[Adjoint]

What Kayerloth said.

I would only notice that Reverse gravity has a shapeable are of up to one 10-ft. cube/level. If the ceiling is higher than 10 ft., Glabrezu doesn't have to extend the spell area to reach the ceiling.
In such a scenario, the creatures afftected would "fall" to the top of the spell area, entering then the area of normal gravity, which would make them fall down again, and enter the area of reversed gravity, so they would start falling up again, and so on. You can imagine a trampoline that pushes them up if they are inside the area of reversed gravity, but once they leave the area, they fall normally back towards the "trampoline".
Eventually the air resistance would slow down such oscillations and they would somewhat stabilize at the border, floating on the top of the area of reversed gravity like a cork on the water. That would make leaving the area of reverse gravity more difficult, as there would be no stable surface thay can walk on or push themselves away from. In such a situation I would treat them as if they were Levitated to that position (as per spell), and incur similar penalities.

[Mike J]

Both the falling rules and Acrobatics say that if you take lethal damage from a fall, you end up prone. I couldn't find a check to avoid it.

If the area extends to the ceiling it will be nasty. Fall, damage, prone. Get up, leave area. Fall, damage, prone. The lost actions from standing up are the killer.

[Adjoint]

Mike J wrote:

Both the falling rules and Acrobatics say that if you take lethal damage from a fall, you end up prone. I couldn't find a check to avoid it.

If the area extends to the ceiling it will be nasty. Fall, damage, prone. Get up, leave area. Fall, damage, prone. The lost actions from standing up are the killer.

And after they manage to get out, glabrezu can use another reverse gravity, since it can use it at will.

[Mallecks]

Do you expect ranged attacks through the area of reverse gravity?

A cursory Google search shows that average arrow flight speeds are between 225 and 300 fps depending on the bow.

Assuming straight horizontal shot, a 225fps arrow will only take approximately 0.022 seconds per square. I would say that the effect of gravity probably doesn't really come into play at close distances that people usually play at (because of the restriction of map/play space). Travelling through the effect for 10 squares only pushes the arrow up about 0.25 meters. This also depends on the number of squares of regular gravity before and after the reverse gravity.

I would not take this into account, as it is not provided by the spell. (Your archer could feel unjustly penalized.) If I did take it into account, it would only be for shots travelling through a high number of squares, which is an unlikely event as the reverse gravity would probably need to be laid out in a way specific to this purpose (and I would give the archer at the least an WIS check to figure it out and just move to side)

Too much trouble. I just wouldn't do it.

[SometimesCrumb]

Mallecks wrote:

Do you expect ranged attacks through the area of reverse gravity?

A cursory Google search shows that average arrow flight speeds are between 225 and 300 fps depending on the bow.

..edited for length...

Too much trouble. I just wouldn't do it.

I do expect arrows to be flying, but your quite right, the short distances would make it too much trouble.

and thanks for clearing things up in my head about this.

[Meirril]

Trying to account for the shifted gravity is just too much of a headache and time consuming to be worth doing. Keep the game moving and just ignore it.

As long as there is a ceiling, its normal ground and combat continues as normal for the caster types. If they were thinking clearly, they would cast fly on the melee types.

If there is no ceiling, then they got the ultimate in bad footing. Still, I can't imagine it being horrible. I'd use a base DC of 10 myself, but I could see 15 (+ spell level) for the concentration check.

Honestly, I've never been impressed with reverse gravity. It just doesn't do that much for the level of the spell.