JoelF said:
First of all, thanks for all of the advise, everyone. Second of all, the DM is in no way abusing us, if anything he's being very creative in dealing with our otherwise successful builds (my Dwarven Defender has an AC of 45 before defensive stancing - for him to hit me in combat has always been a problem without also simultaneously wiping the floor with the rest of the party. The two spellcastes both use all sorts of quickened spells, etc.) I applaud our DM for constantly having to find chinks in our armor which he generally can only use for a short time before we patch up with new feats/spells/equipment or tactics.
The quickened spells don't help vs the gate though since we all fall into it before we even can roll for initiative - only an immediate action such as feather fall or other spell with immediate action casting time can work. Feather fall might slow us enough to have an action before hitting the gate, but alas we didn't have that prepared either (and you still fall 1 foot pretty quick when you're falling 60 feet/ round, so I can see the argument about not even getting to act before then. )
This is the first part where the DM's being an annoyance - you don't have a chance with a Core build unless you're 1) constantly flying (very expensive), 2) immune to planar travel (very annoying, and very likely to turn sour), or 3) immune to being located (and you don't have access to Mind Blank) due to the DM's ruling that you fall on the Wizard's turn (and the Wizard who's attacking you is so far only showing evidence of Core spells, from what you've described - Passwall, Time Stop, Reverse Gravity, and Gate). Due to this ruling, when you lose initiative against this guy (and, as he's on the offense, and strikes from the other side of a wall, you can't WIN initiative), you LOSE, no save - but there are ways to bypass initiative - the Wizard is doing that; Time Stop out of combat, take actions as the spell says, and have you in a "death trap" that takes you some time to exit (but, due to the DM otherwise playing softball, doesn't slaughter your characters).
You've got access to high enough level magic that you can arrange to beat this directly and stick around... but it drips cheese and has drawbacks. I'll get to it later.
JoelF said:
The DM has also ruled that since the caster can control the orientation of the gate, we fall up into it, then down into the abyss out the other side. I'm not sure I agree with that ruling, but I do see it as a grey area which could be argued either way and therefore the DM's interpretation is just as valid as mine. On the other side of the gate we had fallen far enough that by the time we got flying magic going, we were too far from the gate to cross back before the caster dropped concentration and closed it.
The other annoying ruling on your DM's part.
Both are gray areas, to be sure - but do keep in mind that your DM is ruling in the most favorable way for the tactic that his NPC is using.
JoelF said:
The strategic situation also prevents us from using many of the suggestions about staying in an extra-dimensional space and preventing scrying, since we're trying to defend a series of fortifications from the spellcaster, so she knows exactly where we are, and we need to be in the normal world to try to react to her attacks. I like the idea of multiple walls to stop the passwall though - permanent walls of force would be even better.
I'll have to try to convince the wizards to use contingency with greater dispel magic when time stopped, hopefully the caster level check would take down either the reverse gravity or gate and break the combo.
Not legal with Contingency - it has to be a spell which affects yourself. Also not overly likely to succeed - if you've only got access to 7th level spells, you're probably a bit behind on caster level.
***WARNING CHEESE ALERT***
[sblock]Contingent Celerity for the next time it happens. Contingency is 6th, Celerity is 4th. Your party should have access to the spells levels needed. Then cast a Wall spell - I suggest a Wall of Ice, as it can be in any orientation and cast in just about any environment; plus it's low level - in such a way as to block off the Gate.[/sblock]
Edit: Yeah, plus what others have said - Scry/Buff/Teleport (or in your case, Plane Shift/Scry/Buff/Teleport just after he's pulled this on you. I'd normally advise against it, but it's essentially what your DM is already pulling on you, so....