Revised Pillars of Sanity rules

by Tony Williams

(Download a crib sheet for this variant rule).

Greetings. I am a fan of GUMSHOE and, more specifically, Trail of Cthulhu. I’ve been playing RPGs since the early eighties and skew mostly towards Call of Cthulhu and Trail of Cthulhu. I enjoy Trail so much I have created several items to try and make playing the game easier for myself and others. They can all be downloaded at the Trail of Cthulhu Resource page on this website (on the list at the right there click “Trail of Cthulhu“, then “Resources” and look for my name next to stuff).

As I have said I enjoy the ruleset of Trail of Cthulhu; its simplicity, elegance and most importantly how GUMSHOE helps get clues into Investigators’ hands. However I have always felt that the concepts of “Sources of Stability” and “Pillars of Sanity” were somewhat nebulous and maybe could be improved in some way by hardwiring them into the ruleset more directly.

Sources of Stability in particular don’t serve much purpose other than giving the Investigator a peer group which has little to no impact on the game during the actual session. Pillars of Sanity confer no in-game advantage to the player other than defining the mindset of their Investigator and I always felt that if an Investigator has multiple “Pillars” plus a “Drive” their motivations could become difficult to remember (certainly if you are the Keeper and have to be aware of multiple Investigators’ motivations simultaneously). Also, from a player’s point of view, Pillars only offer an attack vector onto their Investigator with no actual benefit other than describing their character’s personality. I wanted to improve Pillars so a player might embrace them more and also let a Pillar give an actual advantage to their Investigator.

A couple of other issues I had with the rules of Trail, as they are, were that Sanity pool points didn’t seem to be eroded often enough for my liking and the use of the Cthulhu Mythos ability was proving too “dangerous” for my players to decide to use it. Excluding the times where Sanity is hit in a BIG way (via a shattered Pillar or meeting a Great Old One) Sanity only tends to be hit in small amounts when an Investigator fails a Mythos-related Stability test that sends them into negative Stability territory. I wanted to increase the opportunities where an Investigator might lose some Sanity pool points.

So… I threw all the ingredients of Sources of Stability, Pillars of Sanity, the Cthulhu Mythos ability and the Sanity mechanic itself into a pot (my brain), stirred them up with a spoon that was covered in some rules from Nights Black Agents, and came up with the following rule amendments:

Pillars of Sanity (Revised)

Types of Pillar of Sanity

There are now four types of Pillar of Sanity:

  • a Moral Stance
  • a Treasured Symbol
  • a Person of Solace
  • a Place of Safety

A Moral Stance is a core belief of the Investigator. It is an abstract concept and is identical to the type of Pillar of Sanity as defined in the Trail of Cthulhu Rulebook. An example would be “The purity of my bloodline.”

A Treasured Symbol is a physical object that inspires or gives hope to the Investigator. Examples could be the flag of the country of origin of the Investigator, a photograph of their family or an object gifted by a close friend.

A Person of Solace is a living non-player character that is dear to the Investigator (this is identical to a Source of Stability as defined in the Trail of Cthulhu Rulebook and therefore the game construct of “Sources of Stability” is deprecated under this rule revision). Examples could be a best friend, a close work colleague or a family member.

A Place of Safety is a specific location where the Investigator feels comfortable and secure when they visit it. Examples could be their place of work, their parents’ house or the site where they first realised they had fallen in love.

Choosing Pillars of Sanity

When a player is creating their Investigator they should define one Pillar of Sanity for each partial set of 3 rating points of Sanity their Investigator has.

Thus for 1-3 rating points of Sanity they should define 1 Pillar, for 4-6 rating points they should define 2 and for 7 upwards they should define 3. Three Pillars of Sanity is the maximum number allowed for an Investigator.

An Investigator can only have one Place of Safety and one Moral Stance as Pillars of Sanity at any one time. An Investigator does not have to have any particular type of Pillar if they so wish. Thus a player could choose three Treasured Symbols if they so desired.

If an Investigator’s Sanity rating falls such that it no longer supports the number of Pillars the Investigator currently has, then the player must choose to “crumble” a Pillar (their choice) and explain why it no longer has any value to their Investigator. There is no further Sanity or Stability penalty for crumbling a Pillar.

Investigators with no remaining Pillars of Sanity suffer a +1 difficulty penalty to Stability tests as per the usual Trail of Cthulhu Rulebook rule.

Regaining Lost Stability Pool Points via Pillars of Sanity

Pillars of Sanity can now be used to regain lost Stability pool points. Each of the Investigator’s Pillars can be used once per game session to do this, but only one Pillar of each type can be used in the same session.

To use their Moral Stance or a Treasured Symbol the Investigator must be in a place of relative calm and safety and must spend a few minutes contemplating their core values or handling or viewing their Symbol. They will regain 1 lost Stability pool point.

If an Investigator can spend at least 6 hours visiting with, talking to or otherwise engaging in normal human interaction with their Person of Solace, without being under threat or placing their Person of Solace in danger, they may regain 2 lost pool points of Stability.

If an Investigator can spend at least 24 hours at their Place of Safety without being under threat or drawing the Mythos to it they may regain 3 lost pool points of Stability.

An Investigator can not regain Stability through their Pillars of Sanity if they are in a mind blasted state (Stability pool points of -6 or less).

Pillars of Sanity and Psychological Triage

Regaining Stability through the Psychoanalysis ability is now affected by Pillars of Sanity.

The difficulty level for the Psychological Triage test is now [ 6 minus the number of Pillars of Sanity the patient possesses ] instead of the standard test difficulty of 4.

Loss of Pillars of Sanity and Mental Damage

Pillars of Sanity can be lost in two ways: via Mythos corruption or in a mundane (non-Mythos related) manner.

Mundane Loss

  • A Moral Stance, because it is an abstract belief, is highly unlikely to be lost in this manner.
  • A Treasured Symbol could be misplaced or physically destroyed.
  • A Person of Solace could die of natural causes or turn against the Investigator for some reason.
  • An Investigator could be evicted from their Place of Safety or it could be demolished or become inaccessible somehow.

Losing a Pillar of Sanity without the Mythos being involved causes the Investigator to suffer Stability rating and pool point loss depending on the type of Pillar lost:

  • a Treasured Symbol – lose 1 Stability rating and 1 Stability pool point
  • a Person of Solace – lose 2 Stability rating and 2 Stability pool points
  • a Place of Safety – lose 3 Stability rating and 3 Stability pool points

Loss involving the Mythos

If the Investigator knows that the Mythos is involved in the loss of a Pillar (e.g. new Mythos knowledge proves a Moral Stance meaningless; a Mythos creature destroys a Treasured Symbol; the Mythos drives a Person of Solace insane or cultists desecrate a Place of Safety) then the Investigator suffers Sanity and Stability pool point loss appropriate to the lost Pillar type.

  • a Moral Stance – lose 3 Sanity pool points and 5 Stability pool points
  • a Treasured Symbol – lose 2 Sanity pool points and 3 Stability pool points
  • a Person of Solace – lose 2 Sanity pool points and 6 Stability pool points
  • a Place of Safety – lose 2 Sanity pool points and 4 Stability pool points

Pillars of Sanity and the Cthulhu Mythos Ability

Successful use of the Cthulhu Mythos ability is now not certain to cause loss of Stability and Sanity pool points.

The more Pillars of Sanity an Investigator has, the greater a chance of protection against losing Stability and Sanity they can have when using the Cthulhu Mythos ability.

Upon successful use of the Cthulhu Mythos ability a test is made against difficulty 5 (the standard Mythos test difficulty). If the test is failed, the Investigator loses pool points of Sanity and Stability depending on the difference between the test die result and the target difficulty according to the table below:


1 – lose 1 Sanity pool point

2 – lose 1 Sanity pool point and 1 Stability pool point

3 – lose 2 Sanity pool points and 1 Stability pool point

4 – lose 2 Sanity pool points and 2 Stability pool points

A player can risk any or all of their Investigator’s Pillars of Sanity as a bonus to the test die roll. For each Pillar they offer, they receive a +1 bonus to the die roll. Players must state which Pillars they are offering (if any) before rolling the test die.

If a test that has Pillars of Sanity backing it fails, then one of the backing Pillars (player’s choice) has been corrupted or shattered by the Mythos revelation the Investigator has just received using the Cthulhu Mythos ability. The Pillar is lost and the Investigator suffers Sanity and Stability pool point loss appropriate to the lost Pillar type as per the amounts for loss of a Pillar via the Mythos described earlier.

The player should try to offer an explanation for how the revelation has corrupted or shattered their Pillar.

How these rule variants might affect the game

Hopefully with these rule suggestions I have simplified the amount of “motivators” describing an Investigator’s mindset since an Investigator can now have only 1 Moral Stance. This means players and Keepers only have to remember an Investigator’s 1 Moral Stance and their Drive when considering their actions. An Investigator could even be “amoral” with no Moral Stance and just have a Drive to motivate them.

Keepers now have other ways to attack Pillars other than relying on Mythos revelations antithetical to the Investigator’s abstract moral concepts. Keepers can launch physical attacks on pillars because three of the new Pillar types are actual physical objects. The Keeper can also choose a mundane form of attack or a Mythos corruption of a pillar to generate different types of mental damage (one way skewing Stability loss versus the other’s Sanity loss).

Pillars now offer an actual tactical advantage to a player because they can replenish lost Stability pool points. I pondered quite a while on the numbers for Sanity and Stability loss/gain trying to strike a balance between reflecting Nights Black Agents’ rules (of Symbol/Solace/Safety) and Trail’s rules for shattered Pillars versus how easy it is for a player to use each type of Pillar in-session and how easy it would be to lose a Pillar (either through a mundane reason or via the Mythos). When choosing which types of Pillar to have for their Investigator players might want to consider the following advantages and disadvantages:

Moral Stance

ADVANTAGE – It is always available for use and can’t be “lost” (in a mundane sense) causing Stability rating loss like the other types of Pillar can.

DISADVANTAGE – It replenishes only 1 Stability pool point. There is a large Stability/Sanity cost if corrupted by the Mythos.

Treasured Symbol

ADVANTAGE – It is easily portable. It has the smallest Stability/Sanity cost of the Pillar types if corrupted by the Mythos.

DISADVANTAGE – It only replenishes 1 Stability pool point. It could be misplaced/taken/destroyed, possibly easily.

Person of Solace

ADVANTAGE – Least likely to be lost via mundane reasons of all the Pillar types. Replenishes more Stability than a Symbol or Stance.

DISADVANTAGE – Large cost if corrupted by the Mythos. Not as readily accessible as other Pillars.

Place of Safety

ADVANTAGE – Replenishes most Stability of the Pillar types.

DISADVANTAGE – Requires most game time to replenish Stability. Large Stability rating loss if it becomes unavailable through mundane reasons.

When choosing Pillars there is also the issue of whether a player wants Pillars they can risk to back the new test for successful use of the Cthulhu Mythos ability which will cause the least grief if they shatter, or do they want Pillars they can use in-session to replenish lost Stability.

A connection has also now been introduced between Sanity rating and Stability replenishment. The lower a character’s Sanity rating the fewer Pillars they will have and thus the harder it becomes to replenish Stability in-session (either by use of the Pillars directly or through in-session Psychological Triage).

Finally, it is now not a certainty that use of the Cthulhu Mythos ability will be damaging to the Investigator due to introduction of some “gamification” through use of Pillars, hopefully encouraging its use more by players. However it still has the potential to shatter a Pillar of Sanity causing a hefty mental hit. If the players are more willing to use their Cthulhu Mythos ability then they face the stark choice of risking a Pillar of Sanity or letting the dice fall where they may (and the odds are such that if they don’t risk a Pillar then they will lose a little bit of Sanity which is something I wanted to work more of into the game).

I hope you feel inclined to adopt these new rule suggestions and do offer feedback in the comments below.

Happy (Slimy) Trails,

Tony Williams.

1 thoughts on “Revised Pillars of Sanity rules

  1. Tony Williams says:

    Zombie article comment:

    I had some questions given to me by a Keeper who is using the above rules. I’ve replicated them below for clarification:

    I’m running a game of Bookhounds and we’re using your revised Pillars rules, which we generally love.

    However, there are serious consequences to their recent actions, and it has triggered a whole bunch of SAN and STA loss, and we have some questions on how the process should unfold.

    A couple of our intrepid PCs encountered an avatar of N and just the first part of the interaction has them both losing 1 SAN. This has reduced them to 6 SAN total, thus propelling them to lose a Pillar. They both have a Moral Stance that would easily crumble under the weight of meeting an avatar first-hand, so that’s great. But we’re unclear on a couple of mechanics, and I wonder if you have any guidance.

    Is there a difference between choosing to crumble a pillar and having it destroyed ?

    The main difference is the meta-game “mechanic” ( not the dice mechanic ) i.e. the how and when ( and truthfulness ) that the player is faced with the knowledge that is causing the Pillar threat.

    Under these variant rules, players only crumble a Pillar at the end of all the dice throwing and Sanity, Stability bookeeping for an encounter. If their new/remaining Sanity rating [ note: NOT CURRENT POOL POINTS ] can no longer support the number of Pillars they have left ( 1-3 supports 1 Pillar, 4-6 supports 2 Pillars, 7+ supports 3 Pillars ) after the encounter, then crumbling happens.

    The Pillar crumbling meta-happens during the encounter role-playing, but the player doesn’t cross any Pillars off their sheet until the total Sanity loss for the encounter is calculated and subtracted from their character sheet. Determine the player character’s remaining Sanity rating at the end of the book-keeping for the encounter, and whether that means they need to crumble some Pillars to agree with the Sanity rating. The act of crumbling at that point ( i.e. the player crossing out their Pillar on their character sheet ) doesn’t cause further Sanity loss because the crumbling meta-happened in the dice-throwing/book-keeping/role-playing part of the encounter.

    Finally, with losing 3 SAN from a Mythos Pillar crumble, wouldn’t that just trigger another Pillar crumbling?

    There is no inherent further 3 point Sanity loss at the point when the player chooses a Pillar to crumble ( i.e. crosses it off their sheet ) – the Sanity loss causing the crumble was worked out during the encounter dice-throwing/book-keeping.


    Todd has 8 Sanity rating and 8 current Sanity pool points

    He has 3 Pillars – Stance ( Purity of Bloodline ), Solace ( his grandmother ), Safety ( his office )

    Encounter 1:

    Todd encounters an avatar of Nyarlathotep and does a Stability test for meeting a Mythos being but fails and has to lose ( for this avatar ) 2 Sanity rating and pool points ( and some Stability ) – at the end of the encounter book-keeping he has ( 8-2 = ) 6 Sanity rating left which only supports 2 Pillars so he has to crumble one – he chooses “Safety” and crosses his office off his character sheet – there is NO further Sanity loss at this point – that was dealt with during book-keeping. The player for Todd needs to come up with an in-story explanation why the encounter with the avatar of Nyarlathotep made him lose faith in his Safety Pillar i.e. his office.

    Encounter 2 [ Todd fully reborn stat-wise ]:

    Todd encounters an avatar of Nyarlathotep and does a Stability test for meeting a Mythos being and fails and thus has to lose ( for this nastier avatar ) 4 Sanity rating and pool points ( and some Stabilty ). During the interaction the avatar of Nyarlathotep convinces Todd his office has been destroyed by cultists ( a case of the Mythos destroying Todd’s Safety Pillar – lose 2 Sanity pool points and some Stability as per table ). Todd crosses off “My Office” from his character sheet. There is no further Sanity loss for crossing off “My Office”.

    At the end of the encounter Todd has an ( 8-4 = ) 4 Sanity rating and ( 8-4-2 = ) 2 Sanity pool points left. A 4 Sanity rating supports 2 Pillars. Todd has already lost his office Pillar in the encounter so only has his grandmother and “Purity of My Bloodline” Moral Stance remaining. His 4 Sanity rating supports these two remaining Pillars and so Todd doesn’t have to crumble any.

    Encounter 3 [ Todd fully reborn stat-wise ]:

    Todd gets his grandmother’s severed head sent to him in the post with the sigil of the cult he is investigating in the box. This is a case of the Mythos destroying a “Solace” Pillar. He loses 2 Sanity pool points ( and Stability stuff as per table ). Todd crosses off “Grandmother” from his character sheet. There is no further Sanity loss for crossing off “Grandmother”. He still has an 8 Sanity rating left, which supports 3 Pillars, but he now only has 2 Pillars still on his character sheet ( Stance and Safety ). Todd doesn’t have to crumble a Pillar and, if his Sanity rating remains at 7 or more, maybe the Keeper might let the player add a new Pillar over the course of time. Note: although Todd’s Sanity rating is 8 his current pool points are now ( 8-2 = ) 6.

    Encounter 4 [ Todd fully reborn stat-wise ]:

    Todd encounters an avatar of Nyarlathotep and does a Stability test for meeting a Mythos being and fails and thus has to lose ( for this avater ) 2 Sanity rating and pool points ( and some Stability ). During the interaction the avatar of Nyarlathotep hands Todd his grandmother’s head ( lose 2 more Sanity pool points as per example 3 ) and convinces Todd he’s a deep-one waiting to devolve ( Mythos destroying Todd’s Stance Pillar – lose 3 Sanity pool points and some Stability as per table ).

    So Todd has to cross out his Stance and Solace Pillars because they were lost during the interaction with the avatar of Nyarlathotep. His Sanity rating has fallen to ( 8-2 = ) 6. His current Sanity pool points are at ( 8-2-2-3 = ) 1. His 6 Sanity rating supports 2 Pillars but Todd only has his single place of Safety Pillar remaining so he doesn’t have to crumble it. Again, if his Sanity rating remains at 4 to 6, maybe the Keeper might let the player add a new Pillar over the course of time.

    If the Sanity rating and point loss for the failed Stability test for seeing the avatar of Nyarlathotep was 5 instead of 3 then the book-keeping for the above would mean Todd would be on ( 8-5 = ) 3 Sanity rating, which only supports 1 Pillar, so he would not have the option to adopt another Pillar over time. However Todd’s Sanity pool points would now be at ( 8-5-3-2 = ) -2 so he would be incurably insane at this point so it’s a bit moot.

    If you read the rule crib sheet ( download link in the article ) carefully I use the words “loss” and “crumble” – they are distinct and different processes and the two mechanisms do not interact or spiral.

    Think of crumbling as a mop-up operation at the end of every encounter that causes Sanity rating loss to make sure all the player characters have the correct number of Pillars remaining based on their current Sanity rating. It doesn’t cause further Sanity rating or pool point loss in itself. The loss of Sanity causing the crumble happened during the Mythos encounter but players crossing off Pillars from their character sheet during the mop-up operation doesn’t cause further Sanity loss.

    One further point to make is that attacks via the “loss” mechanic on players’ Pillars are very active Keeper decisions. In the examples above it would be the Keeper that decided to show Todd his grandmother had been decapitated. Nothing Todd’s player would have done would have caused that to happen ( other than maybe involving his grandmother in the investigation which caused her to be noticed by the cult ). Ultimately it was the Keeper that decided Todd was going to get her head delivered to him. Since there is no “saving throw” against these “loss” mechanic attacks ( they are essentially story beats decided on by the Keeper ) they are powerful ways of eroding a character’s Sanity ( and Stability ) and should therefore be used wisely.

    Conversely “crumbling” is a more player-oriented decision. Players get to choose which Pillars to crumble to tally with their Sanity rating and also come up with the in-story reason for why it happened.

    Hey! Thanks for this! Lots of great details here, and we made it through last night’s session with sanity collapse all around.

    The key point I was missing was how the crumbling of the pillars happens after everything else, and that makes total sense. Thanks again!

    We’ve been playing with the Revised Pillars for a while now. I really do think they work better overall.

    The biggest value seems is the streamlining and reduction of overall details to track. Rather than be 6-8 different items to track with varying degrees of in-game effect, it’s just the smaller list that definitely has impact on how the PCs live their lives. I’m a big fan of “less is more” and this lines up very well with that.

    I think the reduction in the number of “motivators” for investigators ( Drive and upto 3 Pillars and 3 Sources of Stability ) was required. As a Keeper it was getting incredibly hard for me to keep these in my mind when having 3-4 players.

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