I have an adventure that involves consuming native entheogens in order to see and combat the Evil Badness From Beyond Time. The Investigators who do will be tripping balls, and I'm not sure how to handle this, both in the "real" world (where other dangerous, hectic nonsense will be going down) and the weird world of their hallucinations, where I want to frame the perception of and battle with monsters in a unique and scary way. What's the best approach to making this work at the table?

I'd really like some Trail-specific mechanical advice - I've got the research down but I'm not sure how to game this.

  • \$\begingroup\$ I am interested in rules advice and also general "how to GM this situation" advice. But more the former. \$\endgroup\$
    – Jmstar
    Sep 30, 2010 at 12:47
  • \$\begingroup\$ This reminds me of Earthbound and Problem Sleuth at the same time. I like it. \$\endgroup\$
    – Jess
    Oct 6, 2010 at 16:23

5 Answers 5


The first thing is: there isn't an obvious mechanic in Trail of Cthulhu that does this. That is, there isn't an "altered states of consciousness" mechanic. So you get to make up your own. Hooray! It's a sidebar in your adventure.

There are different ways to handle it. Pick some or all of the following.

  1. When you narrate what's happening, you incorporate false things, which are hallucinations. (This one's a given, I think.)

  2. Those hallucinations can cause Stability Checks. For example: you're covered in crawling ants. Make a roll.

  3. Investigators can try to disbelieve what they're seeing. Make a Psychoanalysis Test. If you succeed, you see the real world. If you don't, you fully believe what you're seeing.

  4. Even better...to disbelieve what you're seeing, make a Stability Test. Not a Stability Check (which makes you lose Stability if you fail), but a Stability Test, against a Difficulty Number. If you succeed, you see the real world; if you fail, you fully believe what you're seeing. Thus, you can push yourself to see through the hallucination, but it costs you Stability. This pushes your Stability lower and perhaps (see point 6) the hallucinations get worse. Fun!

  5. Spend a point of Pharmacy (or maybe Medicine) to know what's happening to you. This gives you a bonus on those Stability Tests.

  6. The lower your Stability gets, the worse the hallucinations get. For example, when your Stability goes below zero, the Keeper can narrate things attacking you.

  7. When you're under the influence of the hallucinogens, real horrors cause even worse Stability Checks. For example, you must roll a 6 to succeed, instead of the usual 5. Or you lose 1 or 2 extra points of Stability if you fail.

  8. The hallucinogen actually helps you see the foul patterns underlying reality. Gain a point of Cthulhu Mythos. (Perhaps this happens when you lose a Stability Check. That would be fun.)

  9. Use a variant on the Mental Illness rules. When an Investigator takes the hallucinogen, send the player out of the room. Everyone else decides on something that the GM will describe that isn't actually true. For example, you decide that, whenever the GM describes ants, they aren't really there. (This might be impractical, given that everyone is taking the drug, but some variant of this might be good. Perhaps only do it when someone goes below 0 Stability.)

  10. How about: the more hallucinogens you take, the worse the penalties become, but the easier it is to fight the monster? See how much they'll take.

  11. Look at the Investigator's character sheets for inspiration on hallucinations. Narrate Sources of Stability appearing. Narrate things to shatter their Pillars of Sanity.

  12. When they come out from under the influence, let them regain any Stability lost from hallucinations. (This is a variant of the rule that you regain Stability if you destroy all evidence of the horror.)

(Note: I haven't got the book to hand, so I might have the wrong terminology. To be clear, I say "Test" when I mean "Roll against a Difficulty Number to see if you succeed". I say "Stability Check" when I mean "Roll against a Difficulty number of 4, or 5 if it's a Mythos Shock, and lose Stability if you fail".)

I really like this idea. Good luck with it!

  • \$\begingroup\$ Exactly what I was looking for. Thanks! And welcome! \$\endgroup\$
    – Jmstar
    Oct 4, 2010 at 17:44

Same as everything else in Gumshoes, as clues. I’d allow Investigative abilities to get out of combat and not worry about general abilities much here.

So a few examples that pop obviously to mind.

Anthropology: The Shamans of the Tcho-tcho of Indochina take this drug to open connections with their strange, bulbous spirit companions. From the monograph of Sir Tolliver you do remember a certain chant to appease them.

Art (1 point spend): The swirling lights can be harnassed, turned into beautiful thing of dimensions not of this earth, hurtled against the enemy monsters. Though it does burn the air ina way humanity cannot comprehend but through lenses such as this drug!

Art History: It’s as if the strange enigmatic carvings of a dread city you once studied has come to life. (what you wish to spend a point?) well then you do remember how they were defeated bya culture hero by a swift rain where there should be no rain. Why yes that is a fire house you glimpse in your drug addled state. Though why its folded behind another reality your not sure.

Bargain: All creatures can be bargained with if you know the right words. In your drug addled state they trip out. Are you sure you wish to pay the price?

Cryptography: Strange symbols etch the air, infuse your skin, you struggle, you gain their meaning.

  • \$\begingroup\$ These are great, thanks. Part of the deal is that these terrible monsters are untouchable unless you are whacked out on an enthoegen. And they have allies in the material world, so I need to be able to present rules for both the real-world effects of tripping and the surreal-world fight against the big bad. I want players to be confronted with a difficult practical choice. \$\endgroup\$
    – Jmstar
    Sep 30, 2010 at 15:19

In other games I've had players under the influence before. The approach depends on how much you can rely on them to keep player information separate and how much you need to compartmentalize the information for them.

This is a good situation because the drug is also allowing them to perceive the "monsters," right, so if you tell them they see a monster, is it a real one or just them tripping about a normal dog?

If you are not compartmentalizing information, you can just tell people the different things they perceive. But then it tends to just become "color;" players will occasionally act on the false info but tend not to when it actually matters. If you are just looking for scares, just exercise your powers of description in combat to the tripping characters. When they come to the stairs down, tell them "a huge hundred foot deep chasm opens up below you!" That kind of thing.

If compartmentalizing the information, use passed notes. Have the notes sometimes be the "real" perception of the situation and sometimes the hallucinations. Remember hallucinations aren't all visual "eek there's a monster," there's auditory stuff, enhanced visual (the colors are running!), etc. Did that one party member just make their check to hear something, or is it the drugs? And being in a suggestive state, it's reasonable for two people to say they thought they heard the same thing even if they didn't.

It is even easier if for whatever psychic-whatnot reason they do share the same hallucinations.

Mechanic-wise, I'd use Stability tests to indicate if someone is experiencing a hallucination at any given point (and I'd tend to do it myself behind the screen, because it somewhat defeats the point if they know who is tripping - but then again I'm not a big fan of narrativist play). Much like the mental stability rules, maybe let other non-tripping PCs try to corral them at times.

  • \$\begingroup\$ This is really good advice. Much appreciated. \$\endgroup\$
    – Jmstar
    Oct 1, 2010 at 14:44

Thoroughly research the specific entheogen you plan to use on Wikipedia. Find out (1) where it comes from (Amazon, Southwest, etc.), (2) how its made (what plants/animals it comes from), (3) how its taken (inhaling, ingesting, injecting), (4) its psychological and physiological effects, and (5) how long these effects typically last. You'll want to use some of these elements in your game. For example:

Dimethyltryptamine (DMT) can cause near death experiences (NDE); audio or visual hallucinations; contact with "other beings," alien like, insectoid or reptilian in nature; elevated blood pressure, heart rate, pupil diameter, rectal temperature, and growth hormone. Negative effects can include nausea; sense of pressure in the body; difficulty integrating experiences; fear, terror and panic; dysphoria (bad feelings). Its fast onset can lead one to fall over and hit one's head if not properly prepared. Inhaled, its effects last 5-15 minutes; ingested it lasts 3 hours. Its made in the Amazon by shamans. Its found in virola bark resin or Colorado River toad venom. Its usually made into a tea (Ayahuasca) that must be ingested with a monoamine oxidase inhibitor to be effective. Note that the MAOI you take it with can cause hypertensive crisis, and may have some dependence producing effects, most notably a withdrawal syndrome if discontinued abruptly.

Some of these elements require additional research, e.g., there's a meaty article on the characteristics of a near death experience. There's a good article on Ayahuasca. And there's a section on Amazonian shamanism at http://en.wikipedia.org/wiki/Shamanism#Amazonia

Its important to decide how much of this information the PCs know before they're exposed to it. But you as GM should become well versed in these subjects. This should help you add detail and "color" to your adventure. Good luck!

  • \$\begingroup\$ I'm using two from the Tarahumara pharmacopoeia of northern Mexico. Cyperaceae Scirpus, which the Tarahumara call bakana and mammillaria craigii, known to the Indians as wichuri. \$\endgroup\$
    – Jmstar
    Oct 3, 2010 at 20:44
  • \$\begingroup\$ @Jmstar: Found this in an online botany guide...The name "wichuri" derives from "wichuwa-ka," the native term for "crazy." Its prepared by roasting, removing the spines, then squeezing out the center, often into the ear. Shamans ingest the plant in order to see into a person and find the demons plaguing them. The active compound in it is N-methyl-3,4-dimethoxyphenethyl-amine. Two sources are cited: 1- Bennett and Zing (1935): The Tarahumara: An Indian Tribe of Northern Mexico. 2- Bruhn & Bruhn (1973) Alkaloids and ethnobotany of Mexican peyoti cacti and related specicies in Economic Botany. \$\endgroup\$
    – A. N. Other
    Oct 4, 2010 at 7:33
  • 1
    \$\begingroup\$ Thanks, Elisha. I'm good with the research, what I really need is system-specific advice. \$\endgroup\$
    – Jmstar
    Oct 4, 2010 at 12:33

Presumably, if there is a herb or matter out there made to make you see the Badness from Beyond Time and Space, there should not be a huge drug effect. As for the tripping balls part, I presume the Beyond Time and Space should be trippy enough, that for the actual drug effects all you have to say is, "You feel high"

As for how to make a monster fight trippy, watch some of those Blacklight, theater bits. I personally find those kind of trippy. You could even have the pc's turning the lights on and off to space out the combats which would seem to emulate tripping balls pretty well (ie doing silly and or inconsequential things repeatedly, being really rapt by nothing at all, etc ,etc).


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