The Hidden Shrine, Generally

Poisonous Gas Is Everywhere

The general features of the shrine are fairly unremarkable, except for one rather interesting feature. The lower levels of the shrine, from areas 1 through 38, are filled with a poisonous gas. The gas has two important effects on the environment: it creates a lightly obscured area throughout the affected areas, and it deals recurring poison damage every hour. Be sure to remember about the lightly obscured condition for the purposes of hiding.

Figuring out how long an hour is in any dungeon environment is always tricky, but for starters, remember that a short rest lasts an hour and a long rest lasts for eight hours. The poison damage specified is 1d6 per hour, so any short rest will probably require spending an additional hit die in order to regain the same amount of HP as would be regained without the gas. Since this dungeon is optimized for 5th-level characters, who have 5 hit dice in total to spend, short rests are significantly more costly than usual.

Long rests will be almost impossible, because 8d6 poison damage all at once should be plenty to kill 5th-level characters. Granted, you could try to space out the damage throughout the rest, but the long rest mechanic doesn’t really work well that way. Generally the full restoration of HP is considered to take place at the conclusion of the rest, but no matter how you decide to deal out the poison damage, it’s problematic. I just told my players that they couldn’t take any long rests while in the poisoned areas of the dungeon, and left it at that. Short rests were allowed, but with the understanding that each one would come with poison damage.

As far as how long to wait in table time between one-hour game time poison intervals, remember that you don’t actually have to tell your players that the poison damage happens on an hourly basis. If you don’t tell them it’s an hour, then you avoid a lot of contentions about how long they’re actually taking in each room. Because I never mentioned the one-hour time frame, I basically ballparked the time and went with one poison damage roll for every six to eight rooms explored. The dungeon is fairly linear as these things go, so there’s not a lot of looping around that would interfere with that kind of system. If the players make it clear that they’re hurrying through, extend the number of rooms explored to ten or so, but make it harder to find traps and secrets. Every DM should marry a statistician, and my lovely wife helped me calculate that you can apply disadvantage to Passive Perception by subtracting 4 or so from the original number. And no, that’s not exact, but it’s pretty close.

Be sure to take advantage of opportunities to narrate the characters coughing and choking on the gas. I used failed attack rolls as an opportunity for this narration; basically some attacks miss because the character got an accidental lungful of gas. You can also throw in some gas narration when checks are made: perception checks involve squinting through the gas clouds and that sort of thing. Remember that players forget about recurring effects really easily, so keep reminding them about this one, for flavor and mechanics.

Random Encounters

The module specifies rolling a d12 for every hour spent in the shrine to check for a random encounter. If you want to do random encounters at all, I suggest running them at counterpoint to the poison damage rolls. So, you might get a random roll in room 3, and a poison roll at room 6, and another random roll in room 9, and so forth. Doing both the poison and the randoms at the same time might come across as awkward (e.g., “okay, take 4 poison damage, and some giant fire beetles also jump out at you”), and it’s easy enough to avoid doing that.

Even if you roll for random encounters every six rooms, which is pretty stingy as far as hours passed, remember that there are only 53 rooms in the entire dungeon, which means you’d be rolling for a possible random encounter about 8 or 9 times in total. If you’re rolling a d12 to decide whether a random encounter pops up, you may end up with no random encounters at all. A one-in-twelve chance when you’re only trying 9 times isn’t going to pop up very often. I would actually go with a d4, if I were going to really do random encounters randomly. Or else, I would just toss them in when it felt like the right time, which is what I actually ended up doing.

If you plan on using the random encounters table, make sure you agree with what encounters are likely. I think that panthers and baboons would probably not be happy in a poison gas environment, so I cut them from the batting order. I also only used zombies when the party disturbed someplace where the shrine builders would have interred bodies. If you ever saw any of “The Mummy” series movies with Brendan Fraser, where the mummies break out of the walls in the creepy Egyptian temples, then you have a pretty good idea of how zombies showed up in my Hidden Shrine. “A rotting human arm, wrapped loosely in filthy bandages, thrusts out from the wall and grabs the wizard by the throat. Roll initiative.”

The Olman Language

If you’re running this adventure as a stand-alone, then the Olman language shouldn’t be a barrier, but instead more of a flavor item. Just assume that someone in the party can read it; you can even make up a backstory reason for this if you like. If you’re integrating the shrine into a larger campaign, I would suggest just making the various inscriptions written in Common, or a local language like Chultan. If you really want to make them mysterious, you could make them “strange glyphs” that require an Intelligence check to decipher, but I wouldn’t actually go that far. Rolling checks to attempt to read mysterious writing, over and over, isn’t really compelling gameplay.

Any way you decide to handle the language situation, you need to make sure that at least someone in the party can read the inscriptions. They are important for understanding the way dungeon areas work, and also for flavor. “You see some strange scribblings in a language you don’t understand” is not a good thing to be saying over and over in this module. It damages the party’s chances for success, and it damages the tone of the adventure.

Rooms for Further Thought

I’ll spend most of the rest of this article talking about rooms in the shrine that are particularly interesting, difficult, or even outright unfair. You may want to make some changes to these rooms, or run them with extra care, especially if you’re integrating the shrine into a larger campaign. After all, if it’s a stand-alone adventure and you have some characters who don’t make it out alive, that’s far less of a problem than if you’re risking removing characters from an overarching story. Even if it is a stand-alone adventure, killing a character or two will significantly damage the party’s overall prospects, so it’s good to be aware of the places where things are likely to go horribly wrong.

Area 2: Hall of Thrashing Canes

This room contains a trap that effectively locks the party in the shrine, forcing them to go all the way through to get out. Just make sure you don’t lock anyone on the wrong side of the trap, because then they won’t be able to get through into Area 3, and they can’t escape through Area 1 either without being able to fly or something of that sort. I suppose their friends could come back and throw them a rope down, if they ever make it through the rest of the shrine, but sitting and waiting to be rescued is a lousy way to spend a game session.

Area 7: Sepulcher of Tloques-Popolocas

There’s a lot going on in this room. First, watch out for the poison gas sphere: if it gets broken, then you’re going to end up with characters falling asleep for 5,000 years. Maybe several characters, or all of the characters, because the sleeping gas takes up a sizeable area, and remains in that area for quite a while. The save DC to not fall asleep for 5,000 years is fairly low, but having to make it multiple times is just tempting fate.

There’s also a glyph of warding that sets vengeance in motion in the form of assassins who come to kill anyone who triggers it, but these assassins take their sweet time and show up in a few weeks, well after the characters have moved on to other things and forgotten about this room completely. If you’re planning on using these characters for adventures other than the shrine, these traps are especially problematic.

Also, Tloques-Popolocas can be a pretty formidable enemy, especially if the party has been softened up by poisons and curses and whatnot. Fortunately you can’t really set him loose by accident. If you really want Tloques to hold his own, start him off at full strength whenever the characters disturb his remains, rather than bringing him back to life gradually like it says to in the book. Giving the party two full combat rounds to pound away at poor Tloques while his AC is low and his HP are reduced might end this fight before it even gets started.

Area 19: Silver Coffer

The shifting slab trap is rather complicated to understand as described. This one needs to be puzzled over long before the party ever gets near it. A diagram of how it works would have been a nice addition, but WotC didn’t oblige. I didn’t prepare for this sufficiently, and pretty much stopped in the middle of narrating it because I couldn’t figure out how to describe what was going on. “Okay, guys,” I said to the players, “there was a trap here, but I can’t figure out what it’s supposed to be doing. So I guess there’s not actually a trap here.” I felt pretty silly, as I should have. Don’t make my mistake.

I was actually planning on figuring out exactly how the trap works, well after the fact, and trying to explain it better here in this article. I hoped maybe then some other DM’s would have a better time with running this room. Turns out that I still don’t really understand the trap well enough to explain it any better than it’s been explained in the book. Sorry about that, but I did try.

Area 22: Chamber of the Nacehual

Another one of those 5,000 year unconsciousness poisons can be made with the silvery flask powder and any liquid. Apparently falling asleep for 5,000 years was a really popular thing back in the day.

Area 24: Sandbox

This is a TPK trap, pure and simple. PC’s check in, but they don’t check out. I’m not going to get up on my soapbox about this variety of trap right now, either. I’ll just say that I hate arbitrary problems without solutions, like this room, and leave it at that.

Area 29: Tomb of Pelota

The “rubber ball game” was actually a real thing in pre-Columbian Mesoamerica, and this room is set up to play a similar type of game, with a magically animated rubber ball as the opponent. This is a complex room, so be sure to read the instructions thoroughly, and well before the party gets here.

This is one of those rooms that can be left out of the adventure if you don’t feel solid on how to run the room, or if you think that your players wouldn’t be really interested by it. Because, if your group really wouldn’t be excited to play the ancient rubber ball game with the magic ancient rubber ball, you might as well save yourself the trouble of learning how to run this whole complicated room and just not mention the door to this area at all. There’s nothing plot-critical in here, and the treasure you get isn’t that compelling either.

Area 33: Tomb of Tlacaelel

The doppelganger in the coffin that tries to impersonate a member of the party poses difficulties for you as a DM. Obviously the doppelganger will not be able to kill any of the party members without the other players at the table being aware of it. And, of course, the doppelganger will not be able to fake being the killed party member without everyone at the table knowing about that too. I really hate situations like this as a DM, because requiring players to pretend they don’t know something they know isn’t fair to them, at least in my opinion.

If you want to strike a compromise in this situation, I recommend giving the doppelganger a surprise round against the rest of the party as soon as they come into the room, provided that the doppelganger is impersonating the missing party member. At least that way you can get the replaced-party-member situation out of the way quickly, and we all get on with our lives.

Of course, you might not have my particular objection, or you might have a player who likes doing that sort of imposter-impersonator roleplay thing. Anyway, that’s my two cents’ worth on this room.

Area 35: Xipe’s Audience Chamber

The liquid light is a character killer: once a character touches it, they’re pretty much doomed to death within 2 minutes. Being in darkness, or having a darkness spell cast on the PC will delay the inevitable, provided the players can figure out to do either of those things before the unfortunate liquid-light toucher gets suffocated to death by the stuff. The only way I can think of to permanently relieve this problem and save the character’s life is to amputate the affected limb before the liquid light can spread beyond it. And if you want to try that, you probably have about 20 seconds to figure out you need to cut off that arm before it’s too late.

Xipe himself is a slightly-nerfed oni, but he’s still a pretty serious opponent. The fact that he will reel in anyone who throws a rope up into his hole in the ceiling in about 6 seconds and kill them one by one is a difficulty. Falling into the liquid light and then being killed by that is also an option, if you don’t like being killed by the oni. Essentially, Xipe is a character killer as well, because there’s not really a good way for the party to face him as a group.

So that’s two character killers in one room. Enough said about that.

Area 42: Chapel of Kukulkan

This is kind of an awful room, because you start out by lying to your players about poison gas that is going to kill their characters, and then you spend time throughout the whole sequence of “finding the cure” narrating how they’re feeling closer and closer to death. Yes, it’s suspenseful, but it’s also dishonest. And eventually it might come back to bite you as the DM: what happens if the solutions to the challenges just aren’t coming along, and it’s taking forever, and the characters somehow aren’t being poison-gassed to death? Maybe they even say “well, we give up, let’s sit down and wait to die,” and then they sit down and don’t die because there was never any poison gas to begin with. Now you look pretty silly, and you’ve damaged your credibility.

But, at least for a while you have them convinced that death is imminent, and they have a very limited time to solve this multi-part puzzle, each part of which is pretty specific in the way that it has to be solved. Furthermore, the specific ways in which the puzzle parts have to be solved are kind of arbitrary: why does that glyph controlling the wall of force react poorly to holy water, holy symbols, and holy spells? Well, we don’t know why, that’s just how you have to do it. That’s bad design, guys.

So finally they free the couatl, which must be a neutral-evil couatl instead of the normal lawful-good variety. The whole lying-trickery thing seems a little out of character. A normal, good couatl would just say, “look over here, good-aligned adventurer friends, I’m trapped in this cylinder thing, please let me out.” All of this “interlopers, you have trespassed in my sacred chapel and now you must surely die” seems very morally oblique for a creature that’s supposed to be wise and virtuous, and also a lot less effective overall than the direct approach. Okay, enough of me slamming on the writers. It’s apparently been this way since 1980, and they’re not changing it now.

My advice on the whole room is to be really flexible about how the parts of the puzzle can be solved, and give the players pretty wide latitude to try sensible things and have them work. Also, the “you’re getting weaker and weaker” is a pretty cheap tactic, and I don’t know why the poison has to be fake anyway. I just made the poison real, so if they failed to get the antidote, they would really have died from the poison. Seems like a neutral-evil couatl thing to do.

In Conclusion

The Hidden Shrine is a pretty decent adventure, both as a stand-alone module and as an extra piece integrated into a larger campaign. Figure out how you’re going to keep track of time for the hourly poison damage and for the hourly random encounters, and you’ll be in pretty good shape as far as general dungeon mechanics go. Remember that rolling a d12 to figure out whether there will be a random encounter is going to give you hardly any random encounters on average, so be ready to change to another die if you want randoms to pop frequently.

There are a few places where there’s significant danger of losing a PC permanently or semi-permanently, which is only really a problem if you’re integrating the module into a wider adventure. Falling asleep for 5,000 years will ruin your day as an adventurer, after which it will proceed to ruin your next 1,826,249 days in a row. And yes, that’s including leap years. Of course they have leap years in D&D; don’t be silly.

The sandbox in Area 24 is a total party kill trap, and Xipe and his liquid light in Area 35 are both ways to kill off your party one character at a time. Also, if you take my advice and just make the poison gas in Area 42 for real instead of just an unnecessary couatl lie, you can get a TPK in there as well, but at least there’s a chance to escape from that one.

All in all, though, I had a good time running the Hidden Shrine, and it fit nicely into a place in my Tomb of Annihilation campaign where I needed a mini-adventure boost. Along with the Sunless Citadel and Dead in Thay, that makes three modules from Tales from the Yawning Portal that I like. Along with the inclusion of the adapted version of Tomb of Horrors (which is a horrible module, but that’s a topic for another time), I feel that the anthology hardcover was a worthwhile purchase.