Had a session this week, and I'm not sure I made the right calls. I'd like it if some people could weigh in on how this is supposed to work. If anyone's curious, we were playing Rappan Athuk, and this took place in room 8-16, but that shouldn't be necessary to adjudicate these calls.
Scenario: Three trolls were in their troll liar, surrounded by all their loot. The rogue of the party asked to trade, so the trolls let him (and him alone) into their lair. Two trolls surrounded him, and another blocked the doorway, to prevent the other PCs from entering. The rogue began discussing what to trade for what.
The party sorcerer/oracle is outside the liar, with the rest of the party. He is a gnome with a monstrous spider mount (as a class feature via nature mystery); he casts greater invisibility, which (due to the power of his companion's "share spells" ability) makes both him and the spider invisible. The trolls have no spellcraft, but they know casting when they hear it, and get upset and yell "no magic!" and get on edge.
The gnome&spider begin crawling up the walls & ceiling of the troll liar, over the guard's head. (Spider has climb speed.) Invisibility is not auto-succeed, but instead grants +20 to Stealth while moving.
first question: how many Stealth checks needs to come out of the gnome's player? One each for mount and rider? Does the rider get the +40 bonus for not moving? Can one assist the other? This is a tense situation, but we're not technically in combat: can either of them take-10?
The trolls each roll a Perception check (with a small penalty for distance) and fail, so negotiations continue with the rogue.
The gnome wants to cast a touch spell on one of the trolls surrounding the rogue. So he skitters up adjacent to the troll to cast.
second question: the gnome&spider just entered my threatened area (trolls have 10ft reach); does this allow me to make an additional Perception check? Or do I look back at the previous die roll I made, then simply remove the distance penalty for him now being closer to me?
The gnome then casts a spell (ghoul touch) and goes to touch the troll. The spell has a verbal component, and thus must be spoken "in a strong voice", so the trolls definitely hear it and therefore know that there's "more casty" going on. But because it's greater invis, this hostile action does not break the spell. Therefore, the gnome elects to not cast on the defensive.
third question: can the troll take an AoO? Do I automatically "pinpoint the square" because I heard the verbal component? Or is there a Perception check involved? (Obviously, if I get an AoO, it would be made with 50% miss chance)
That ends that little scenario. But we ran into a very similar scenario later that same session. (Room 6A-9, if curious.) The setup was pretty similar, the key difference is that the floor of the room was quite sandy: not enough to count as hindered terrain, but enough to leave very obvious tracks.
fourth question: when the gnome&spider approach the trolls to perform the ghoul touch, do the trolls automatically know what square the PC is in? (Spider-tracks look completely different from troll-tracks, and they just beeline straight into the fray.)
fifth question: if the gnome wanted to cover his tracks, how can he? I believe it would involve Survival, but who rolls: him or the spider?
Thanks in advance!
First, that's not how share spells works. Share spells lets you cast on your bonded creature INSTEAD of yourself. To cast on both at once requires the feat Improved Share Spells, which shortens duration.
To your actual questions:
1) The spider is trying move stealthy, so it needs a stealth roll. It's ambiguous for the rider. GM call. I like your +40 for not personally moving.
2) When one character rolls stealth, the others who might perceive it roll perception. Bonus rolls as they move closer would be house-rule, I think. They can also use perception intentionally on their turn.
3) Speaking while invisible gives -20 to Perception DC according to PFSRD. Haven't doublechecked it. Beyond that I can't find any RAW mechanical effects.
4)Seeing tracks on the ground would be a GM-discretion stealth/perception conditional modifier.
5)Covering tracks on the approach would likely be a part of the stealth roll to move unseen. Doing it on the trail to discourage tracking, not sure, maybe survival then.
First question: I would say only the spider needs to make stealth checks, once per move action. The rider is just sitting there quietly. Spider gets the +20 bonus for Invisibility. If you really want to enforce that the sorcerer needs to be stealthy too, then make him roll stealth with the +40 modifier for invisibility and not moving (his spider is moving but he's not). None of this is "rules" per say, but there isn't going to be a rules answer to cover this so it's really up to you. Also note that since the trolls heard spellcasting and got upset, you could have them on high alert - any troll on any round could take a move action to look around for sneaky enemies, getting an active Perception check against the last Stealth check(s) rolled by the sneaky spider and/or gnome. I don't think the rider can assist the mount or vice-versa since they're both just trying to be sneaky. For aiding another, you have one person attempting a skill but the people aiding him are not attempting the skill, they're just attempting to aid - since both are attempting stealth (regardless of whether you insist on the sorcerer rolling it or not), they are not eligible to aid each other. Take-10 is probably allowed for stuff like this but you could rule that they are in "immediate danger" since a failed roll means instant combat, surrounded, by nasty trolls - either ruling is fine.
Second question: the spider and gnome make their stealth checks with each move action, opposed by new perception checks from each troll. Moving in or out of a threatened area doesn't change this. Make new rolls each time a check is needed.
Third question: Hearing the Gnome means the trolls know he's there, casting a spell. They cannot take an AoO ("You can't execute an attack of opportunity against an opponent with total concealment, even if you know what square or squares the opponent occupies." - CRB, Total Concealment). The Gnome's casting doesn't break invisibility but he's no longer being stealthy when he's casting an attack spell. So the trolls get a Perception check against DC 0 (not stealthy) + 20 (invisibility) + any other modifiers, like distance. If they make it, they pinpoint his square, if they fail, they still don't know where he is. if one of them makes it, he can point to the square as a free action, telling his comrades where to attack.
Fourth question: Sand is soft ground. Survival skill is used to track. It's an everyman skill so everything can use it even with no ranks. Soft ground is DC 10 to track. Use this to set a DC for a Survival skil - anyone aware of the tracks can pinpoint the invisible spider's square by making this check, as described in the "invisbility" special ability in the appendix.
Fifth question: I don't know. I can't find a rule for covering your tracks. Survival skill seems as good as any, but covering tracks usually means wiping them away, often using branches or bushes like a broom - this isn't very quiet. You also can't cover the tracks where the spider's 8 legs are standing so those will always be visible. Doing this while sneaking past an alert (or even a distracted) guard should still give him a Perception check to see the tracks anyway, so I don't think it would matter. Without an immediate observer, I would say this becomes an opposed survival check - the one covering the tracks sets the DC that the tracker has to overcome to find them - but that would only matter if the tracker (trolls) aren't there watching right at the same time that the tracks are being made and being covered.
first question: how many Stealth checks needs to come out of the gnome's player? One each for mount and rider? Does the rider get the +40 bonus for not moving? Can one assist the other?
I would agree that under normal circumstances, only the mount needs to make the stealth check. Although it wasn't mentioned, I would probably require a ride check from the rider; riding up the wall on the spider's back without moving around would not be something I'd say the gnome could do automatically. If the ride check failed, then I would require a stealth check from the rider (with only the +20 bonus from being invisible).
second question: the gnome&spider just entered my threatened area (trolls have 10ft reach); does this allow me to make an additional Perception check? Or do I look back at the previous die roll I made, then simply remove the distance penalty for him now being closer to me?
Entering a threatened area does not automatically allow for a perception check against an invisible creature. Unless they had moved a distance sufficient to require a second stealth check (I believe they would probably be moving half-speed?), then the troll remains blissfully oblivious.
third question: can the troll take an AoO? Do I automatically "pinpoint the square" because I heard the verbal component? Or is there a Perception check involved? (Obviously, if I get an AoO, it would be made with 50% miss chance)
Since the spell specifies that you must speak at a particular volume, I would probably forego the perception check to know that there's something nearby. The troll(s) would still have to make a perception check to pinpoint the square from whence the sound came; in this case, the DC for the perception check would be at a -20 per the Invisibility special condition (effectively cancelling out the bonus for being invisible).
fifth question: if the gnome wanted to cover his tracks, how can he? I believe it would involve Survival, but who rolls: him or the spider?
Unless the spider has some ability that would allow him to cover his tracks, I would require a survival check from the gnome to do so; assuming that you wanted to get back to (and up onto) the wall on the spider so that you could lean down and cover the final set of tracks, I would probably require a ride check at that point also.
I like the ride check to see if the gnome should be +20 or +40 to the stealth check. I would make the spider make the check as the spider is moving.
There would be no second check for moving into a threatened area.
I would give a new perception check to hear the casting of the spell. As stated this DC is at a -20 plus other modifiers.
As to the tracks, I would just say it is part of stealth. Yes, a troll could still use survival to see and follow tracks, but not perception. Stealth is about everything involving hiding, not just sight. Walking around puddles and sticks, finding rocks to stand on rather than sand and other moves should be included in the stealth check. This won't make tracking any more difficult, but I don't think it should be used to find someone stealthing in the middle of combat.
YMMV.
Excellent point, meowstef: Unless these are core rules ice trolls (which for some reason don't have scent), then the moment the gnome moves within 30 feet of the trolls, they know he's there, without a perception check; if he gets within 5 feet of them, he's pinpointed automatically.