Say I want to make one or more foes sink in Abaddon by opening a Gate under their feet, should they receive a Ref save to avoid falling inside or should the spell stay true to its "Saving Throw: none" entry?
The reason there is no saving throw is that it has no target. Therefore, you can't target it on an individual, and they don't have to make a save.
That's not to say you can't do as you are talking about, only that the person is not the target of the spell.
Personally, I'd rule they get a reflex save to 'jump' off it as it manifests. That's assuming they don't have a held action to just move off when you start casting.
I'd make the reflex fairly easy as well, probably 10+caster's dex mod (just gotta be faster than him completing the spell). Of course, if you can catch them flat footed, that helps.
Say I want to make one or more foes sink in Abaddon by opening a Gate under their feet, should they receive a Ref save to avoid falling inside or should the spell stay true to its "Saving Throw: none" entry?
It's not typically a combat spell for the purpose of dropping somone into hell, but kudos for creativity. As a Dm I'd say the target gets a reflex safe to get out of the way as you manifest, but theres nothing stopping you from telekenetically combat maneuvering them into the hole assuming you can concentrate on both spells.
Open a gate tied to the elemental plane of water horizontally above a fire elemental-esque target. that'd be fun. Or horizontally at the upper limit of a valley to make a lake.
WOOT 9th level spells!
I'd make the reflex fairly easy as well, probably 10+caster's dex mod (just gotta be faster than him completing the spell).
That would imply "identify the spell or get no save" and "how can you identify that he'll open the Gate under your feet?".
If not the same DC as it would be if the spell itself offered a save, then I'd go more on the DC of something like a trap.
By RAW they get no save, though a DM can give them a save to jump out of the way since it is being offensively.
Once created if someone bull rushes, ki throws, etc. someone through the gate they get no save.
Just in to close it before they decide to step back through the gate.
Since you can place it anywhere on the other plane you would want to dump them 200 ft above ground so they fall if they do not have a fly speed and take 20d6 and get stuck on the other plane, oh and perferably into an active volcano, a Solar's bedroom, etc.
According to the basic Conjuration rules:
A creature or object brought into being or transported to your location by a conjuration spell cannot appear inside another creature or object, nor can it appear floating in an empty space. It must arrive in an open location on a surface capable of supporting it.
The gate would not "arrive in an open location", and so the spell should fail.
Since the spell doesn't mention this as a possible attack, I'd just treat it as a normal ad hoc save, probably a reflex save DC 15.
You can't place the gate where an object occupies the space. So nice try, but no.
The gate is bidimensional like a shadow, casting it horizontally on the floor doesn't cross occupied spaces, as shadows themselves don't, unless walls, trees or other things are inside its would-be-area.
There is no rule for it because it is not an intended use. You can try to see if the DM allows it, but he may also use it against you. If you are the DM I would not allow it.
RPG Superstar 2012 Top 32
|
You can't place the gate where an object occupies the space. So nice try, but no.The gate is bidimensional like a shadow, casting it horizontally on the floor doesn't cross occupied spaces, as shadows themselves don't, unless walls, trees or other things are inside its would-be-area.
The space of the creature is occupied space.
The space of the creature is occupied space.You can't place the gate where an object occupies the space. So nice try, but no.The gate is bidimensional like a shadow, casting it horizontally on the floor doesn't cross occupied spaces, as shadows themselves don't, unless walls, trees or other things are inside its would-be-area.
Good point, I'll support that
But the gate is not in the space of the creature. It is beneath it, and doesn't have a third dimension that would make it occupy any real space, in that position.
But the gate is not in the space of the creature. It is beneath it, and doesn't have a third dimension that would make it occupy any real space, in that position.
When in doubt rule against it, I would count a creature standing in the space as an occupied space and thus would not allow the portal to appear, wether the portal actually has no 3rd dimension does not matter if you approach it from a game mechanic point of view.
If someone is standing on the surface there is basically no space between 'someone's' feet and the ground, so you can not place a portal in the 'no space' area.
|
But the gate is not in the space of the creature. It is beneath it, and doesn't have a third dimension that would make it occupy any real space, in that position.When in doubt rule against it, I would count a creature standing in the space as an occupied space and thus would not allow the portal to appear, wether the portal actually has no 3rd dimension does not matter if you approach it from a game mechanic point of view.
If someone is standing on the surface there is basically no space between 'someone's' feet and the ground, so you can not place a portal in the 'no space' area.
Gate + quickened hydraulic push might be your best trick. Although a lot of creates your CMD role isn't going to beat. Having your BDF with a readied action to bull rush the creature through the gate would work best.
|
I'm surprised that [a certain poster] has not popped in here to tell you that you cannot force anyone through a gate, no matter what (ie bull rush, hydraulic push etc), due to the wording of the spell.
...anyone who chooses to step through the portal is transported.
Since the target of your tactic can choose not to go through the gate, he couldn't be forced to. In fact he would probably further state that the target could in fact walk around on the surface of a horizontal gate without passing through as long as he chooses not to pass through the portal.
:)
Cheers
I'd make the reflex fairly easy as well, probably 10+caster's dex mod (just gotta be faster than him completing the spell).That would imply "identify the spell or get no save" and "how can you identify that he'll open the Gate under your feet?".
If not the same DC as it would be if the spell itself offered a save, then I'd go more on the DC of something like a trap.
You don't need to identify the spell. Just realise something is happening below you and jump out of the way before the ground gives way. The pit series of spells has a similar concept, but those are written for this express purpose.
I'm surprised that [a certain poster] has not popped in here to tell you that you cannot force anyone through a gate, no matter what (ie bull rush, hydraulic push etc), due to the wording of the spell.
...anyone who chooses to step through the portal is transported.Since the target of your tactic can choose not to go through the gate, he couldn't be forced to. In fact he would probably further state that the target could in fact walk around on the surface of a horizontal gate without passing through as long as he chooses not to pass through the portal.
:)
Cheers
I think you're technically correct, but mostly because it says "functions as plane shift" and plane shift is willing creatures only.
Although I think walking on the event horizon of a horizontal plane is tantamount to "choosing" to fall in the hole, or being bull rushed through is tantamont to having the choice made for you."Ultimately it's DM's call, but I see that very powerful 9th level spell as essentially being a rip in the multiverse. It can be negotiated as any mundane archway. I'd say that if one is using it as an offense that the save is very easy to jump out of the way. If used in conjunction with a bull rush (or similar enemy moving tactic) that it's completely legit. In fantasy it's not uncommon for the hero to be pulled into the void/abyss/etc as they are forcing the enemy into it.
|
There's nothing in the spell description to suggest that pressure and forces equalise between the two 'sides' of the Gate, and if they don't, then the gravity from the other side doesn't pull you through just 'cos the Gate manifests beneath your feet (if it can)... unless you happen to be falling at the time (so are 'moving' in that direction anyway). So even if you assume the Gate is 2-D, and that you can manifest it beneath someone's feet, then in that situation they do get to walk around on the surface of the thing...
Of course, if your DM rules that pressure and forces do equalise between the two sides of the Gate, then using it to dump people into Hell is the least of your problems as far as weaponising the thing go... 'I'll open a Gate to the Elemental Plane of Water... how much pressure is that water under?'
The only way the spell normally allows for using just the spell itself to pull something through the Gate is the Calling version - and you need to be on a different plane than your target to cast that... plus you need to place the spell so that they arrive on a solid surface which can support them (as per normal Calling rules) - so no dropping them from 50,000ft... sorry... ;p
Say I want to make one or more foes sink in Abaddon by opening a Gate under their feet, should they receive a Ref save to avoid falling inside or should the spell stay true to its "Saving Throw: none" entry?
I'd give the foe a Reflex save to get out of the way while it's forming, similar to Create Pit, Transmute Mud to Rock, Wall of Stone, etc.
An idea hit me.
Cast gate horizontal above target, use a greater quicken metamagic rod to quicken a reverse gravity. Or have another PC delay till you cast gate to cast the reverse gravity.
Wee!
|
|
Gate functions as a plane shift. Plane Shift does not transport creatures who are not willing to travel. Since gate does not state differently, the NPC can just choose to not have the gate effect it.
This is like using Dimension door to transport you and the person grappling you vertical 400 ft +40ft/level. There is no saving throw in the dimension door spell, since it only moves willing targets.
If someone is standing on the surface there is basically no space between 'someone's' feet and the ground, so you can not place a portal in the 'no space' area.
The lack of a third dimension means it has no space in that dimension. Unless a creature or object have a part of itself that goes below ground (tree roots, ground bindings, etc.), ground and creature's feet/object's supports are separate entities between which a bidimensional plane does exist (x, y plane, not game's planes like Hell and Abyss), and since the gate is a bidimensional plane...
Of course the entire area where the gate would open must be flat and devoid of physical entities (and maybe some magical ones, like a Wall Of Force and other things) that are half above and half below grounds.
I'm surprised that [a certain poster] has not popped in here to tell you that you cannot force anyone through a gate, no matter what (ie bull rush, hydraulic push etc), due to the wording of the spell.
...anyone who chooses to step through the portal is transported.Since the target of your tactic can choose not to go through the gate, he couldn't be forced to. In fact he would probably further state that the target could in fact walk around on the surface of a horizontal gate without passing through as long as he chooses not to pass through the portal.
Gate functions as a plane shift. Plane Shift does not transport creatures who are not willing to travel. Since gate does not state differently, the NPC can just choose to not have the gate effect it.
____________
Gate:
"Casting a gate spell has two effects. First, it creates an interdimensional connection between your plane of existence and a plane you specify, allowing travel between those two planes in either direction.
Second, you may then call a particular individual or kind of being through the gate.
The gate itself is a circular hoop or disk from 5 to 20 feet in diameter (caster's choice) oriented in the direction you desire when it comes into existence (typically vertical and facing you). It is a two-dimensional window looking into the plane you specified when casting the spell, and anyone or anything that moves through is shunted instantly to the other side.
A gate has a front and a back. Creatures moving through the gate from the front are transported to the other plane; creatures moving through it from the back are not.
Planar Travel: As a mode of planar travel, a gate spell functions much like a plane shift spell, except that the gate opens precisely at the point you desire (a creation effect). Deities and other beings who rule a planar realm can prevent a gate from opening in their presence or personal demesnes if they so desire. Travelers need not join hands with you—anyone who chooses to step through the portal is transported. A gate cannot be opened to another point on the same plane; the spell works only for interplanar travel."
____________
The "choice" thing is only about the difference with Plane Shift that each creature is independant from the caster to make the travel.
There's nothing in the spell description to suggest that pressure and forces equalise between the two 'sides' of the Gate, and if they don't, then the gravity from the other side doesn't pull you through just 'cos the Gate manifests beneath your feet (if it can)... unless you happen to be falling at the time (so are 'moving' in that direction anyway).
It's not the gravity of the other side that would pull a creature down, but the gravity of the plane it is in at the moment of casting.
The new gravity would affect it only once it passes to the other side (so, if the gate is kept open, the creature would be constantly falling between the two planes, assuming that a horizontal gate opened on the ground here must be horizontal and on the ground at the destination too).It could be said that creatures (and everything else) are constantly falling, when under the force of gravity; it's just that they are stopped by the floor. But if a hole suddenly opens on that floor...
About the Elemental Plane of Water, it has objective gravity, if I recall right, so no water would cross the gate opened in it, unless some force directs gravity there.
About the Elemental Plane of Water, it has objective gravity, if I recall right, so no water would cross the gate opened in it, unless some force directs gravity there.
You may be right about the gravity thing, however if we're using real world physics as a basis than the water pressure alone is enough to send copious amounts of water through a gate. Assuming the gate is underwater on the elemental plane of water side (and it has to be hence the name of the plane) Gravity would be unnecessary. Additionally once a small amount of water is brought through by any amount of pressure the relative gravity on the prime material would assert on that water and cause a vacuume effect.
It's TOTALLY munchkin and cheesy, but it's not an overly dramatic effect for a 9th level spell that requires concentration.
About the Elemental Plane of Water, it has objective gravity, if I recall right, so no water would cross the gate opened in it, unless some force directs gravity there.
You may be right about the gravity thing, however if we're using real world physics as a basis than the water pressure alone is enough to send copious amounts of water through a gate. Assuming the gate is underwater on the elemental plane of water side (and it has to be hence the name of the plane) Gravity would be unnecessary. Additionally once a small amount of water is brought through by any amount of pressure the relative gravity on the prime material would assert on that water and cause a vacuume effect.
It's TOTALLY munchkin and cheesy, but it's not an overly dramatic effect for a 9th level spell that requires concentration.
What causes water pressure is gravity pulling down everything above it. Deep sea divers need to deal with it because of the mass of water above them being pulled down on top of them. If there is no gravity in the elemental planes, there will be no pressure.
Think of a blob of water floating in zero gravity. Is it in a rush to get anywhere on its own? Nope. It will flow with air currents and the like. The surface tension might be enough to keep the water on its side of the gate.
Assuming the magical hole that was ripped in the fabric of the universe decides to play by our rules of physics.
I think there is also some problem with using the word "space" both as the (real world)" volume occupied by an object in 3 dimensions" and the (game term) "5' grid square on the battlemat" that is a source of part of this argument.
About the Elemental Plane of Water, it has objective gravity, if I recall right, so no water would cross the gate opened in it, unless some force directs gravity there.
You may be right about the gravity thing, however if we're using real world physics as a basis than the water pressure alone is enough to send copious amounts of water through a gate. Assuming the gate is underwater on the elemental plane of water side (and it has to be hence the name of the plane) Gravity would be unnecessary. Additionally once a small amount of water is brought through by any amount of pressure the relative gravity on the prime material would assert on that water and cause a vacuume effect.
It's TOTALLY munchkin and cheesy, but it's not an overly dramatic effect for a 9th level spell that requires concentration.
What causes water pressure is gravity pulling down everything above it. Deep sea divers need to deal with it because of the mass of water above them being pulled down on top of them. If there is no gravity in the elemental planes, there will be no pressure.
Think of a blob of water floating in zero gravity. Is it in a rush to get anywhere on its own? Nope. It will flow with air currents and the like. The surface tension might be enough to keep the water on its side of the gate.
Assuming the magical hole that was ripped in the fabric of the universe decides to play by our rules of physics.
I think there is also some problem with using the word "space" both as the (real world)" volume occupied by an object in 3 dimensions" and the (game term) "5' grid square on the battlemat" that is a source of part of this argument.
Good point. So a caster would have to pierce the event horizon to cause a small amount of water to come onto the prime and thus be affected by it's gravity. The vacuum effect + waters natural tendancy to bind together (surface tension) would take care of the rest. Still functional, but with an extra step.
Still do-able, but still cheesy, but still underpowered use for a 9th level spell. Frankly Wish would probably be more effective or a decanter of endless water...or two.
|
|
It's not the gravity of the other side that would pull a creature down, but the gravity of the plane it is in at the moment of casting.
If that's the case, then the surface resistance of the floor under the 2-D Gate would also still function, and the guy standing on it wouldn't fall through the Gate. Basically, you can't logically have it both ways - either the Gate is an 'open' hole through which everything passes - pressure equalises, forces like gravity act, the heat from the elemental plane of fire fries you, etc.... or it's a 'window' or 'membrane', through which you can move if you so choose, but through which nothing passes otherwise. Your game, your choice... but try to be consistent! ;)
It's not the gravity of the other side that would pull a creature down, but the gravity of the plane it is in at the moment of casting.If that's the case, then the surface resistance of the floor under the 2-D Gate would also still function, and the guy standing on it wouldn't fall through the Gate. Basically, you can't logically have it both ways - either the Gate is an 'open' hole through which everything passes - pressure equalises, forces like gravity act, the heat from the elemental plane of fire fries you, etc.... or it's a 'window' or 'membrane', through which you can move if you so choose, but through which nothing passes otherwise. Your game, your choice... but try to be consistent! ;)
A couple of points. It's hard to get tone across in type, but I mean this respectfully.
A) It's fantasy. It works however the Dm says it works.
B) A gate membrane can be semipermable. The closest comparable is Stargate. They have a very detailed view of how this COULD work according to real world physics. That too is fantasy, but as best as I can tell they're reasoning is sound though obviously unproven. Google it.
C) The gate is 2d with no mass. Assuming equal opposing gravitational forces on each side and the "open hole" concept (or at least permable by the object in question) with a horizontal event horizon, an object (such as a person) would fall from the side he is on until the gravitational forces of the opposing side countered them. I imagine it would look a lot like bobbing back and forth in mid air. In a very short period of time the objects mass would be equally distributed on both sides. Essentially the object or person would be floating in mid air, identical to the effect described in the reverse gravity spell. Of course if it is attached to the plane of water the person could simply swim to the other side and he/she wouldn't sink in as far since the elemental plane of water has no gravity. In that case the object or person in question would be balanced by their boyancy vs the pull of gravity on the originating plane.
Sorry amateur physics professors. :)
If you had the posited neutral gravity water plane on the other side, and someone dropped through the gate, he'd go shooting through the water on the other side. It would look like he'd been shot out of a cannon at whatever speed he could generate for falling his height.
Buoyancy doesn't come into it. You get buoyancy due to gravity. It's the pressure of the water pushing up due to all the water around it pushing sideways, which occurs because gravity is pulling down on it. Air pushes down on air, which pushes down on water, which pushes down on earth. Since it can't go down, you get lateral pressure as well. Since the human body is not as dense as water by volume, it doesn't have as much mass as the water, and get's pushed up by pressure.
In the posited situation, the character would shoot down through the gate (due to gravity on this plane pulling on him) and into the water plane. Since there is no gravity there to provide pressure, he'd just push through the water until friction from rubbing the water slowed him down (assuming he didn't try to swim and slow himself down).
The acceleration rate of gravity on earth is about 9.8 meters per second per second. A normal person is about 1 meter tall at most. So he'd accelerate for about a 10th of a second, and be moving at about a meter per second on the other side of the portal. So he wouldn't move all that fast on the other side, but without gravity, and only friction with water to slow him down, he'd go quite a ways.
Sorry amateur physics professors. :)
If you had the posited neutral gravity water plane on the other side, and someone dropped through the gate, he'd go shooting through the water on the other side. It would look like he'd been shot out of a cannon at whatever speed he could generate for falling his height.
Buoyancy doesn't come into it. You get buoyancy due to gravity. It's the pressure of the water pushing up due to all the water around it pushing sideways, which occurs because gravity is pulling down on it. Air pushes down on air, which pushes down on water, which pushes down on earth. Since it can't go down, you get lateral pressure as well. Since the human body is not as dense as water by volume, it doesn't have as much mass as the water, and get's pushed up by pressure.
In the posited situation, the character would shoot down through the gate (due to gravity on this plane pulling on him) and into the water plane. Since there is no gravity there to provide pressure, he'd just push through the water until friction from rubbing the water slowed him down (assuming he didn't try to swim and slow himself down).
The acceleration rate of gravity on earth is about 9.8 meters per second per second. A normal person is about 1 meter tall at most. So he'd accelerate for about a 10th of a second, and be moving at about a meter per second on the other side of the portal. So he wouldn't move all that fast on the other side, but without gravity, and only friction with water to slow him down, he'd go quite a ways.
We're debating the physics of a magic portal to a place that doesn't exist. So you can keep the condescention to yourself, Mr. Sister. ;-)
Though I do agree with several of your points. A person would go shooting through the water due to lack of gravity until friction stopped them. The "no gravity" thing throws me off. Though if it's a person I would give them a swim check to at least stay near the portal. Probably easy for someone unencubmered, but more of a problem for someone in armor or falling from a great height on the prime before they hit the portal.
It could be an interesting way to kill a large nasy creature that you know can't breath underwater. Just shut the portal behind them.
Though I do agree with several of your points. A person would go shooting through the water due to lack of gravity until friction stopped them. The "no gravity" thing throws me off. Though if it's a person I would give them a swim check to at least stay near the portal. Probably easy for someone unencubmered, but more of a problem for someone in armor or falling from a great height on the prime before they hit the portal.It could be an interesting way to kill a large nasy creature that you know can't breath underwater. Just shut the portal behind them.
I think the best use of this tactic would be to get rid of nasty objects. For example, if there's a cursed item that needs to be gotten rid of, levitate it up an inch and then drop it through a portal to some outer realm (shadow, hell, negative energy plane, positive energy plane, etc).
Even something really heavy could be raised up on block and tackle, or levered up enough to cast the spell under it and then released.
Though I do agree with several of your points. A person would go shooting through the water due to lack of gravity until friction stopped them. The "no gravity" thing throws me off. Though if it's a person I would give them a swim check to at least stay near the portal. Probably easy for someone unencubmered, but more of a problem for someone in armor or falling from a great height on the prime before they hit the portal.It could be an interesting way to kill a large nasy creature that you know can't breath underwater. Just shut the portal behind them.
I think the best use of this tactic would be to get rid of nasty objects. For example, if there's a cursed item that needs to be gotten rid of, levitate it up an inch and then drop it through a portal to some outer realm (shadow, hell, negative energy plane, positive energy plane, etc).
Even something really heavy could be raised up on block and tackle, or levered up enough to cast the spell under it and then released.
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.
I prefer the image of the Pally drop kicking the lich into a portable hole.
Then when the lich dusts himself off and laughs at the stupid pally, the pally grins and tosses in a handy haversack. :)
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.I prefer the image of the Pally drop kicking the lich into a portable hole.
Then when the lich dusts himself off and laughs at the stupid pally, the pally grins and tosses in a handy haversack. :)
I love this game. ;-)
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.I prefer the image of the Pally drop kicking the lich into a portable hole.
Then when the lich dusts himself off and laughs at the stupid pally, the pally grins and tosses in a handy haversack. :)
By the way, You and I have both just proven ourselves to be SUPER alpha nerds. I love how this game posit's fantasy and lets us discuss things like relative gravity.
By the way, You and I have both just proven ourselves to be SUPER alpha nerds. I love how this game posit's fantasy and lets us discuss things like relative gravity.
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.I prefer the image of the Pally drop kicking the lich into a portable hole.
Then when the lich dusts himself off and laughs at the stupid pally, the pally grins and tosses in a handy haversack. :)
LOL
UBER, not SUPER. :)
By the way, You and I have both just proven ourselves to be SUPER alpha nerds. I love how this game posit's fantasy and lets us discuss things like relative gravity.
True, but I really like the imagery of the pally drop kicking the evil lich into the positive energy plain.I prefer the image of the Pally drop kicking the lich into a portable hole.
Then when the lich dusts himself off and laughs at the stupid pally, the pally grins and tosses in a handy haversack. :)
LOL
UBER, not SUPER. :)
semantics
Sorry amateur physics professors. :)
If you had the posited neutral gravity water plane on the other side, and someone dropped through the gate, he'd go shooting through the water on the other side. It would look like he'd been shot out of a cannon at whatever speed he could generate for falling his height.
Buoyancy doesn't come into it. You get buoyancy due to gravity. It's the pressure of the water pushing up due to all the water around it pushing sideways, which occurs because gravity is pulling down on it. Air pushes down on air, which pushes down on water, which pushes down on earth. Since it can't go down, you get lateral pressure as well. Since the human body is not as dense as water by volume, it doesn't have as much mass as the water, and get's pushed up by pressure.
In the posited situation, the character would shoot down through the gate (due to gravity on this plane pulling on him) and into the water plane. Since there is no gravity there to provide pressure, he'd just push through the water until friction from rubbing the water slowed him down (assuming he didn't try to swim and slow himself down).
The acceleration rate of gravity on earth is about 9.8 meters per second per second. A normal person is about 1 meter tall at most. So he'd accelerate for about a 10th of a second, and be moving at about a meter per second on the other side of the portal. So he wouldn't move all that fast on the other side, but without gravity, and only friction with water to slow him down, he'd go quite a ways.
We're debating the physics of a magic portal to a place that doesn't exist. So you can keep the condescention to yourself, Mr. Sister. ;-)
Though I do agree with several of your points. A person would go shooting through the water due to lack of gravity until friction stopped them. The "no gravity" thing throws me off. Though if it's a person I would give them a swim check to at least stay near the portal. Probably easy for someone unencubmered, but more of...
Depends on whether gates interact with gravity at all. If there's no interaction then the gravity of the current plane acts as normal and the subject can fall in the gate (you can create a harmonic oscillator if you gate into a plane with objective "up" gravity). Now if there is interaction then I believe you would just do the simple vector addition and naturally give everything a 1/r potential (we don't need to worry about GR and QG for PF)
I think there are a couple issues here. One of them is the nature of the game's physics. Does gate make a hole, like in Portal? Or is it a semipermeable membrane that can only be crossed with intent? Either way, I think, is fine. They both carry different implications for magical and planar theory, and so should be thought about.
The second issue is if you can force people through a gate. With regards to the original question, I don't think Reflex is an appropriate save. While, thematically, it may be appropriate it is not so in a mechanical sense. Reflex is never used for lethal or game-ending effects. I'd say Will would be a better save (at a DC equal to what the gate would have if it allowed a save). It's also thematically cooler. You don't jump away from the open portal - you hold yourself on this plane by force of will alone.