So, here's the situation. The dungeon I will be putting my players through is currently occupied by a trio of hags. One of the hags in this coven has had difficulty with this group before, so they are not going to take it lightly. The only way into the top chamber where the hags are is to use a teleportation pad and the hags know the players are coming. They will be watching the teleportation pad with clairvoyance. As soon as the players look like they're about to use the pad, they'll cast forcecage around the arrival point (I'll put the duration on that at 1d4+4 rounds to account for a couple of rounds delay in them going up.
The way I have this encounter planned out, the hags want to first get rid of the mage (because he can dispel their magic as well as disrupt their casting and do serious magical damage, but will be the easiest one to take out with their spells). What I have laid out is that when the players teleport in, the coven will immediately target the mage with baleful polymorph to take him out of the fight. If the mage is polymorphed, the two melee focused characters will not be able to get to the hags, and the cleric will have to dispel the polymorph in order for him to be able to dimension door them out, or she'll have to try taking the hags on in a spell fight for a couple of rounds while the melee characters have their thumbs up their butts. If the mage gets initiative on them, he can cast dimension door and get the party out of the forcecage, meaning the hags will go for different tactics, since trying to use coven magic while in easy melee reach of adventurers is not a wise tactic for several reasons.
But as I was thinking about this, it brought up a question. If the hags are watching through clairvoyance and cast forcecage enough ahead of them coming up that it could have as many as 4 rounds of its duration expended, would that mean they could get a surprise round here? Because the players won't know what is on the other side of the teleportation pad, but the hags will be watching and preparing to act as soon as they arrive. If they get a surprise round, that kinda changes everything, because that means the mage has no chance to get initiative on them and it is totally a matter of making a fortitude save (the mage's worst) to avoid being removed from combat for at least 1 round - potentially longer if the hags can disrupt the cleric on the next round.
The surprise round can be avoided, obviously, if the players expect the hags to be on the other side of the pad, which they might. They know who they're going after in this fight (it's a dangling plot thread I've been meaning to wrap up for a while) and they're smart enough to guess the pad might go directly into an ambush, especially since there is the hag's charmed troll servant bellow that they could force to reveal the secret. If they state they prepare to attack as soon as they arrive, initiative will definitely resolve normally.
If the hags see the PCs (with clairvoyance), then yes, they will be ready. If they see the PCs enter the room with the teleporter, but then start doing other stuff and don't see when a PC is about to use it, then No, since even though you know someone 'might' be coming, their appearance could still give them a chance to react to seeing you first (the hags shouldn't be surprised, by they still might not react faster than a speedy, or lucky rolling, PC). So as long as the hags are watching, then yes.
You didn't ask for more, but I wanted to say that your set up is a little straight-forward and really doesn't take advantage of all the fun things the hags could do to set this encounter apart from any other wizard or magic-user with a forcecage.
Longish:
Here's some fun things you can try instead. Fair warning, some are not as efficient or effective as others, just fun and interesting. Also, I don't know what hags make up the coven. I will assume green hags (at least one). Also, if the hags want to make sure they have some time, leave something in the origin room with the teleport pad, to distract the PCs. It can be as simple as a book or journal or collection of pictures. As long as the PCs notice it and it looks like it isn't a direct trap (though it could have one on it, like fire trap or something for believe-ability depending on what it is). For instance, if it looks like a forgotten journal or diary of one of the hags, it should possibly have some entries from earlier (or those pages are ripped out and only recent ones are left). They talk about the hags' plans (real or not) and maybe talk about allies or cohorts amongst the nearby towns (real or not), etc. You can even type this out as handouts and if a player reads them, you can keep track of time and assume every 6 seconds spent reading or discussing is a round of preparation for the hags.
1a. The hags have a brazier or fire burning near the destination point. When the PCs are about to step on the teleporter, a green hag uses her pyrotechnics power to generate a smoke cloud, then they use forcecage as a 10x10 cube, with no windows. It seems you have 4 PCs, so they should all fit in there. Depending on the timing (both spells will only last 1 rd/level, probably 9 if no hag is higher than that), the PCs will not be able to see at all, may be weakened by the smoke cloud, and will need Fort saves (DC 15 + 1 per check) or spend the round doing nothing but choking and 2 consecutive rounds will cause non-lethal damage, softening them up.
Granted, the hags can't really do anything additional during this time but prep, so here's a more complicated alternative. It kind of depends on the room size and lair, so may not be completely feasible.
1b. As above, but the hags have multiple braziers or fires spaced around the destination point (at least far enough away that the smoke from one won't obscure the flame of the others and make them untargetable). Then, using the 20x20 barred forcecage (they don't need to have LoS to place that), they keep the PCs trapped in the cage while one smoke cloud keeps them blinded as above, and the green hag pyrotechnics a new one as the first is about to expire, thus potentially extending the smoke inhalation and hinderance on the PCs while the other hags do their things (can't target the PCs directly though). So might be good if one the hags have an aqueous orb or flaming sphere to cast in and roll around during this time. This works even better if the hags have a magical fire, since that won't be extinguished and can be used over and over (if the hag can see the fire).
2. Layer the forcecage with the cube over the destination and the cage around that cube. the 10x10 cube will fit within the 20x20 cage. You can either have it centered, giving you a five-foot walkway around the cube, or have the cube in a corner of the cage. Normally, your PCs would all arrive in the cube, since it sounds like you have four of them and they should all fit. However, if any of those spaces are occupied, then most teleport effects will move them to the nearest open space. So if you can have the hags place a sizable obstacle, furniture, etc. in one or two spaces, then this will effectively split the party.
Bonus points, for realizing the hags know the PCs are coming and have used their animate dead power on some corpses I am sure they have lying around (maybe not human), to make either skeletons or zombies (easy fodder for the cleric of course). Have them place two in the destination area (where the cube will encase) and the rest around it. This means two PCs will arrive at the destination in the cube, and have to deal with an undead and the other two will end up outside that area within the cage and have their own to deal with while also have to deal with any nastiness or effects the hags toss in. This also means that the mage can't touch all of them to dimension door them out without going into each section first.
Additional bonus points for utilizing the pyrotechnics plan above (or just a really smoky brazier) to keep the PCs from knowing they're just fighting simple skeletons or zombies in the smoke (and possibly unable to talk and communicate with all the coughing and choking). At the very least, the undead should be veiled to not look like simple, easy-to-turn undead.
More bonus points, for making the undead veiled to look like the individual PCs themselves. The hags can't know which PCs will go first beforehand, so a PC might end up in a section with a doppleganger of themselves or a teammate. If the smoke comes into play, they may not know which creature is their real ally or not without spending a round asking and having to wait for a reply in combat.
3. I assume the hags know what the PCs' home or base of operations looks like (having viewed it with clairvoyance at the least). If the journal or time-buying distraction is left in the teleporter room, one of the last entries talks about the hags taking the fight to the PCs and setting the teleporter to take them to attack them at home. They use mirage arcana to make their area look like the PCs' base or a room at the inn they stay at (possibly damaged if you want to look like an attack happened). They also use veil to make themselves look like any allies or other known patrons or staff that might be there (possibly looking injured). Depending on that set up and likely story, they could get the PC's to lower their guards, weapons, waste a healing spell or powerful magic either trying to help or locate the hags (they all should have mind blank obviously, which apparently stops even true seeing in Pathfinder, which I don't like, but there it is). Also, there could be aforementioned animated dead which are also veiled (and probably even mindblanked too, they both last a long time), either playing as corpses (since they aren't very good actors at other roles likely) and waiting to rise up. The hags (in disguise), might claim the hags are still nearby, possibly invisible (green hags have that at will). That will let them attempt charm monster, baleful polymorphs, or bestow curses while the party tries to sort things out, and any successful saves that are detected as hostile tingles can be deflected away as saying that the hags must be launching an attack on them. One of the disguised hags might even mention feeling a strange tingle, as though something was trying to affect her mind first, so as to foreshadow this and throw off suspicion, their spell-like abilities don't have components (other than requiring a full round action from each), as long as they aren't doing anything else it shouldn't be noticeable unless a PC is very perceptive (don't just ask if they take an AoO unless you do that normally for supposedly friendly or neutral targets). Note that the hags either need to plan what to do or have a code for determining what power and target they plan to focus on, since saying "Hey sisters, let's charm the fighter," might be a giveaway.
Of course, the mirage arcana might conceal dangerous areas of the actual lair: a pit, rough floor, etc.
4. Similar to 3, but depending on the lair layout, the mirage arcana looks like a forest and one or two of the hags (green hags) use their treeshape ability to resemble a tree or shrub or other plant suitable for the area. One hag maintains appearances (using animated dead under veil to resemble the other two, or even more hags than there actually are). The undead don't do anything but defend themselves, but this lets the 'lead hag' at least call out audibly what she feels the other two need to concentrate on doing for their coven powers, since as trees they can't talk. It appears she's talking to the decoys, but is really letting the treed hags know who and what to focus on casting while they likely remain unnoticed and unattacked by the PCs for the first few rounds. Again, note that their mindblank likely makes them harder to discern, and the 'lead hag' may actually have invisibility up as well, which with the mindblank is supposedly some great combo in Pathfinder (at least until she attacks).
And yet another example of why my Wizard started routinely using Detect Scrying as a daily spell about as soon as he had more than a couple 4th level slots.
But yes unless the PCs take some pretty specific steps to say they prepare for an ambush upon teleporting I'd say the hags get if not outright surprise a hefty bonus on their initiative.
And those fighter/melee types had better not be sitting on their thumbs. At minimum they can at least try and knocking a chunk out of the Forcecage albeit dealing with Hardness 30 and 260hp+ is rough
it's not unbeatable by a power attacking melee expert. And then there's potions of various sorts which might get them out ... though you and the DM presumably know what if any options they might have there.
Personally I wouldn't make it a surprise round, I'd make it a readied action.
If the Hags were watching the party and attacked them without waiting for an action it would be a surprise round, but the Hags are waiting for the party to instigate the fight.
Both ways of doing this end up with the Hags getting a standard action before the PCs get to act, but with a surprise round the Hags may also win initiative and get another round in before the PCs. With a readied action the Hags only get the one action before the PCs.
Also as Claxon pointed out the PCs should get a reactive perception check to notice the sensor. If they do notice it (or if they're just paranoid) the can ready an action for what to do when they step through the sensor.
Depending on what triggers the readied actions of the Hags vs the readied actions of the PCs, there may need to be an initiative (or perception) roll to see which readied action goes off first.
Clairvoyance has a duration of 1 minute per level and doesn't say it requires concentration to maintain, so I assume that the hags could have it active, take a round to put up the forcecage and then go back to checking the sensor to make sure they know when they're about to step through the teleport pad.
The pyrotechnics plan is interesting. I'll work that in, probably. The rest I'll have to think about. I have time to rework the plan, so I might make that work.
I did forget about the check to spot the sensor, though. My main concern here was that the encounter was fair and if they have a chance to spot the sensor, then it seems pretty fair. Especially since the cleric has put lots of ranks into perception, so the chances of not spotting the sensor are low if they think to make perception checks - which they probably will, seeing as they're in a hostile location.
I did forget about the check to spot the sensor, though. My main concern here was that the encounter was fair and if they have a chance to spot the sensor, then it seems pretty fair. Especially since the cleric has put lots of ranks into perception, so the chances of not spotting the sensor are low if they think to make perception checks - which they probably will, seeing as they're in a hostile location.
They should get a perception check even if the players don't think of it. You could handle this a few ways:
- Ask them to roll perception to see it. This may end up with some metagaming, as the players know there's something to see even if they don't roll high enough perception.
- Ask them for their perception modifiers ahead of time and have them take 10. Any time they get a perception roll and you don't want them to know about it you just assume they rolled a 10 and add their modifier. Then you can check to see if they if they passed without even rolling dice. The problem here is that you might find yourself metagaming since you know what stealth will beat their perception.
- What my group does is ask each player to roll 20 or so perception rolls in advance and tell the GM. The GM can randomise the order, then write them all down. Whenever there's a "secret" perception check the GM just crosses off the next number on the list and tells the players if they succeed on the check. This way requires a little more work, but we like it.
They should get a perception check even if the players don't think of it.
If they automatically get a perception check for this, then it's pretty much a moot point. The DC to spot the sensor is 20+level of the spell (23). The party is 13th level at this point (these aren't standard hags, one is a witchfire the other two are winter hags, long story on the witchfire), and the party rogue has put a rank into perception every round. If he takes ten, he'll spot it for sure, but if he rolls a regular check, he can only fail on 6 or less (even lower if his trap senses get to be added).
But, as someone else helpfully reminded me, they do have access to veil and animate dead. They aren't going to get a surprise round, but some clever usage of the veil will allow them to have a chance that the players spend most of their first round focused on some skeletons. That should give pretty close to the same advantage.
Oh, that raises a thought: the witchfire is an incorporeal undead. If she hides herself INSIDE the wall, but is still within 10 feet of the other two hags, does that enable them to coven cast? Or would the fact that she can't see them prevent that. Or, hell, maybe the barrier prevents them from making a connection. Still, an interesting idea.
