Horror and Insanity in Hollow Earth Expedition

By Daniel Potter & S.D. Hilton

Occasionally, a person is confronted with something beyond their capacity to comprehend. Dinosaurs, though wildly improbable to encounter in modern times, are not beyond the abilities of the human mind to understand. Museums, academic studies, and popular fiction have all paved the way for characters to accept these and other fantastic things. However, there are other things so horrible, so frightening, so unlike anything that a normal person has ever dreamed possible, that when faced with the reality, they are forced to reconsider their own place in the universe. Some things are simply not meant to be. Some things are simply beyond the human mind’s ability to cope. When a character is forced to confront such things, they are likely to suffer ill effects.

Hollow Earth Expedition isn’t a game about the hopeless spiral into insanity, so these rules try to balance character horror with playability. Playing “crazy” should be fun, not a chore for the player. Horror and insanity revolve around the use of some new Attributes and the concept of Compelling Flaws. The basic mechanic is analogous to physical combat, pitting a sighting’s Horror rating versus a character’s Sanity rating, so it’s fairly simple to use, though the effects are quite different.

Horror rating

Horror-inducing creatures, locations and events are collectively called sightings. All ‘’sightings’ ‘have a Horror rating, and in all cases it is rolled in opposition to characters’ Sanity. For creatures and places, it is an assigned Secondary Attribute (that is, it’s in the stat block). For events, it is up to the GM to decide whether it warrants a Sanity roll, and if so, to assign a Horror rating. Some examples follow:

Horror rating 2

  • Seeing an animal sacrificed in a bloody and gory manner.

  • Seeing a person tortured but not killed.

Horror rating 4

  • Seeing a vampire dusted in the rays of the Sun.

  • Seeing an inanimate object animate.

Horror rating 6

  • Seeing a person turn into a werewolf before your eyes.

  • Seeing a ghost enter a person’s body and possess it.

Horror rating 8

  • Opening the door of your home and finding 100 skinned corpses littering your living room.

  • Watching the inhabitants of an entire apartment complex walk to the highest floor and jump off in unison.

Horror rating 10

  • Being aware of a ghost taking over your body.

  • Seeing the occupants of a large cemetery all crawl out of their graves.

Horror rating 12

  • Learning that all of the dead of the world have reanimated.

New Secondary Attributes


Shock represents your character’s inherent resistance to mind-bending effects. Your character’s Shock is calculated as follows:

  • Shock = Willpower

Characters with high Shock ratings aren’t disturbed easily by the strange and horrible, while characters with low Shock ratings may find it difficult to function normally while under great stress from things that don’t conform to their world views.


Sanity represents your character’s sense of self and mental fortitude. Your character’s Sanity is calculated as follows:

  • Sanity = Charisma + Willpower

Characters with high Sanity ratings may be able to function normally and complete an investigation involving a victim of cannibalism, while characters with low Sanity ratings may find it difficult to complete basic tasks around the grisly carnage of the scene.

Horror Rolls

When a character is witness to a sighting, the GM makes a single Horror roll and compares the result to individual Sanity rolls by all characters present (remember to modify Sanity rolls for possessing Compelling Flaws, see below). The degree of success of the Horror roll is termed the impact of the sighting.

Impact less than 0: If the Horror roll results in fewer successes than a character’s Sanity roll, that character is unaffected by the sighting.

Impact equals 0: If the Horror roll and a character’s Sanity roll result in the same number of successes, the character is stunned per the normal rules (see Effects of Damage, p.128 Hollow Earth Expedition).

Impact greater than 0 but not greater than Shock rating: If the impact is greater than zero, but does not exceed a character’s Shock rating, the character is stunned for one round, and becomes Horrified (see below).

  • Example: Impact 2; Shock rating 2; the character is stunned for one round and horrified.

Impact greater than Shock rating: If the impact exceeds the character’s Shock rating, the character is stunned for one round, becomes horrified, and gains a Compelling Flaw (see below).

  • Example: Impact 3; Shock rating 2; the character is stunned for one round, horrified, and gains the Compelling Flaw Obsessive-compulsive (ties and unties shoes repeatedly).

Impact is greater than twice Shock rating OR character suffers critical failure on Sanity roll: If the impact is greater than twice the character’s Shock rating, or the character’s Sanity roll results in a critical failure, the character is stunned for one round, becomes horrified, gains a Compelling Flaw, and may not attempt to regain composure (see Horrified, Regaining Composure below).

  • Example: Impact 7; Shock rating 3; the character is stunned for one round, horrified, gains the Compelling Flaw Obsessive-compulsive (ties and unties shoes repeatedly), and may not attempt to regain composure.

Hordes of Horrors

Sometimes a character will suffer a number of sightings in a short amount of time. Repeated sightings make it more difficult to maintain rationality, which is reflected by the Horror rating being increased above the base for subsequent sightings. For each sighting after the first in a single scene (the GM decides when a scene ends), the Horror rating is raised by two for each previous sighting. This way the continual battering of the character’s Sanity begins to break down even the most stable character.

  • Example: Treasa’s Shock rating is 2, Sanity rating is 5. Treasa has tracked a pair of demons to their lair. As she enters the lair she discovers the demons have covered all the mirrors with the skinned faces of their victims, and drawn in eyeballs. This is a Horror: 4 sighting. Horror roll yields 2 successes; Sanity roll yields 3 successes; Treasa absorbs the event unphased. As Treasa enters the next room searching for the pair, she steps on something that pops with a liquid ooze under her foot. Her flashlight slowly beams downwards where she sees all the missing eyes from the victims covering the floor. This is also a Horror: 4 sighting, but because this is the second sighting in the scene, it is raised to 6. If Treasa beats the Horror roll this time, she will be able to act normally until the next sighting which will have its Horror rating increased by +4.

Shock Checks (Optional)

Optionally, a group may decide that not every gruesome situation will require a Sanity roll, and what triggers a roll for one character may not trigger one for another. This is accomplished through a Shock check. If the character’s Shock rating is greater than or equal to the average result of the sighting’s Horror rating, he is immune to the shock of that particular event, and doesn’t need to make a roll.

  • Example 1: Shock rating 3; Horror rating 4 (avg. 2); Shock rating is greater than the average Horror roll, no Sanity roll necessary.

  • Example 2: Shock rating 3; Horror rating 7 (avg. 3+); Shock rating is less than the average Horror roll, character has to make a Sanity roll.

Repeated Sightings

A character may have to make a Sanity roll the first time he has a sighting of a particular type, but once exposed to certain knowledge, doesn’t have to roll versus the same type of thing later. For instance, once you’ve seen ghouls feeding, you don’t have to make a Sanity roll the next time you see the same thing. Admittedly, this could be a bookkeeping nightmare, so we’ll leave it to the players to determine how they want to handle it. You could simply keep a list of “immunities” on your character sheet, for instance, “vampires, flayed corpses.”

A Note on Courage Rolls

The line between a sighting that requires a Sanity roll and a mundane event that only requires a Courage roll can be blurry, and requires GM discretion. Discovering (that is seeing, not just hearing) that vampires are real and are feeding on victims in Hoboken would require almost any character not familiar with the existence of vampires to make a Sanity roll. A chamber crawling with giant tarantulas may be a Courage roll for your average stalwart adventurer, but most GMs will require a character with the Arachnophobia Flaw to make a Sanity roll. It’s even possible that you might have to make both a Sanity roll and a Courage roll in some cases.

Gaining Compelling Flaws

As explained above, a Compelling Flaw is gained when the impact of a sighting is greater than a character’s Shock rating or a character’s Sanity roll results in critical failure. A Compelling Flaw is assigned by the GM and is frequently related to the event that caused it, though it doesn’t have to be. If seeing a vampire for the first time triggers a Compelling Flaw, a character may feel a need to scrawl crosses on everything he sees, rub garlic over his body constantly, or may be petrified at the sight of blood due to the fear that it may attract vampires. Though the GM has final say in assigning Compelling Flaws, players are encouraged to make suggestions. See the sidebar with sample Compelling Flaws.

State of Being


If your character fails a Sanity roll, he is horrified and only capable of taking limited action. Being horrified is somewhat similar to being exhausted or disabled, but the character may not exert to ignore the condition. By default, the condition lasts for the remainder of the scene, but it is possible to recover before this.

A horrified character loses his Active Defense. Whether previously engaged in combat or not, a horrified character must choose to attack, defend or move, and will only perform that action during the entire time he is horrified. This represents a character going berserk, becoming slack-jawed, or running off blindly. Alternatively, the character may also follow one of his Compelling Flaws to the exclusion of other activity; while this activity might be, by happenstance, beneficial in some small way (such as scratching crosses on things to ward off vampires), it shouldn’t be as beneficial as some more purposeful action.

If you want to add more “insanity” into the process (e.g., lack of player choice), roll two dice on the table below to determine what the character does.

- / -Attack (go berserk)
- / +Defend (stand still)
+ / -Move (run away)
+ / +Compelling Flaw (or Move)

Regaining Composure:

To recover from being horrified, characters make a Sanity roll versus a difficulty equal to the impact of the Horror roll that horrified them; this is an extended action with the number of successes required equal to twice the difficulty. Characters that critically failed their Sanity roll, or were overcome by an impact more than twice their Shock rating may not attempt to regain their composure. Otherwise, if one of the following circumstances arises, you may make the attempt.

If you can remove yourself from the presence of the sighting (or be removed), you may attempt to regain your composure. This could be as simple as exiting the room and shutting the door, as difficult as running several miles away through underbrush, or might be entirely impossible. Frequently, leaving the horror’s presence is the same as the end of the scene and so would require no action.

If other characters attempt to help you, you may attempt to regain your composure. This help could be in the form of restraint, striking for damage (hopefully nonlethal), or some other action.

You may spend two Style points to attempt to regain your composure.

You may spend Style points to improve your chances on composure rolls per normal Style rules. Note that if the condition allowing for an attempt to regain composure is disrupted, so is the attempt, and the process must be started from scratch if it again becomes possible.

Compelling Flaws

A Compelling Flaw is not a choice a character makes, but is instead a reaction to things beyond his ability to deal with. Compelling Flaws are something that a character cannot help but do on a regular basis. They should come into play enough to hinder the character, but shouldn’t become a major stumbling block to the story. Compelling Flaws can be overcome but it is difficult (see Treatment and Recovery below).

Gaining Compelling Flaws: Compelling Flaws are usually gained through failed Sanity rolls, but could also be the result of a disease or some foul curse. Most Compelling Flaws are mental or social in nature, though some are physical. Many are simply regular or Severe Flaws that are “upgraded” to Compelling status. Regardless of origin, a character should succumb to a Compelling Flaw as soon as it is gained.

Succumbing to Compelling Flaws: A character can succumb to Compelling Flaws under three circumstances:

First, when the impact of a Horror roll results in a Compelling Flaw, a character may immediately succumb to that Flaw, rather than one of the other reactions to being horrified (attack/stand/run).

Second, a player may decide that his character succumbs to one of his Compelling Flaws whenever appropriate.

Third, the GM may trigger a Compelling Flaw. When the GM does so, a player may pay two Style points to ignore the Flaw for the scene; this cost must be paid at the time the Flaw is triggered.

Regardless of the reason for succumbing, once it happens, the character should act accordingly whenever possible throughout the remainder of the scene.

Gaining Style points: A character may not gain Style points for succumbing to Compelling Flaws during the adventure in which they are gained, but may in subsequent adventures if he chooses to forego treatment/recovery.

Modifiers to rolls: Each Compelling Flaw a character possesses imposes a -2 penalty to all Sanity rolls, as well as Empathy rolls for treatment/recovery.

For each time a player triggered a Compelling Flaw during an adventure, the character receives a cumulative +1 bonus to his next treatment/recovery roll (that is, if you succumb 3 times during an adventure you get a +3 bonus).

Treatment and Recovery

No one enjoys being traumatized, and most characters will hope for recovery from sanity-breaking sightings. Some will simply try to tough it out on their own, while others will seek professional help. The effect of being horrified simply wears off after the allotted time and has no lasting effect upon a character, but Compelling Flaws require more.

If a character is suffering from one or more Compelling Flaws, he may shake off the affects in time. As long as a character is attempting to recover, he cannot gain Style from any of his Compelling Flaws. Once he ceases these attempts, he may gain Style from any remaining Compelling Flaws as normal. A player who has stopped seeking recovery, may restart the process from scratch at a later time. If a character does not succumb to a Compelling Flaw at all during an adventure, the character is not entitled to make a treatment/recovery roll between adventures and loses any potential bonuses he might have gained.

While a character is undergoing treatment, or attempting to recover on his own, the difficulty for all Sanity or Empathy rolls is equal to the highest impact of the sightings which resulted in Compelling Flaws for the character (i.e., a character who has gained Compelling Flaws from impacts of 3 and 5 would roll against a difficulty of 5). A successful roll enables the character to eliminate one Compelling Flaw. For each adventure, a player may make one of the following rolls, depending on the character’s circumstances:

  • Natural recovery: At the beginning of an adventure (not necessarily session), the player may make a Sanity roll. This represents the natural healing that may take place during the downtime between adventures.

  • Psychoanalysis: A character with the Empathy Skill (preferably with the Psychology Specialization) may attempt to treat the character. This is an extended action, with the total number of successes needed equal to the twice the difficulty, and each roll taking a number of hours equal to the difficulty. When the number of successes reaches the total needed, one Compelling Flaw is eliminated, and the process starts over for the remaining Compelling Flaws. Note that only one roll may be made per adventure, so the process could take several adventures to complete. Also, this could be rolled “offstage” like the first roll, or could be roleplayed as the players prefer.

    • Example: Highest impact 4; difficulty 4; total number of successes needed 8 (4 x 2); hours per roll 4.

Treatment/recovery rolls are subject to the modifiers for possessing and succumbing to Compelling Flaws noted in that section. Two other modifiers also apply:

  • Motivation: If a character successfully performs an action that is in line with his Motivation (GM makes the final decision) it earns the player a +2 bonus. The character has done something that reaffirms his reason for living.

  • Amazing success: If a character performs an action, achieving an Amazing success (+5 Degree of Success) or greater it earns the player a +2 bonus. The character has had a “break” in their “episode” as they find a moment of perfection that helps them refocus their mental outlook.



Sample Compelling Flaws

Genre Options

The goal of these rules is to provide a means for players to get a little “crazy” without sacrificing too much playability. Players should have fun, and be relatively unafraid to face the horrors that await them, rather than run from everything for fear they’ll lose their minds. In other words, the goal was to recreate pulp horror, not Lovecraftian horror. That said, some playgroups will want to lighten things up even more while others will want to darken them, or at least make things a little more difficult for the characters.

Compelling Flaws (lighter): Compelling Flaws might be completely ignored, only using the horrified state of being.

Horror Ratings (lighter): Horror ratings could be lowered which would result in less frequent frights.

Horror Ratings (darker): Horror ratings could be raised across the board by a set amount; this would pretty much guarantee a regular amount of running and screaming, as well as more Compelling Flaws.

Treatment/recovery (darker): Only allow recovery through medical intervention, even when the difficulty is low enough for a character to accomplish without help.

Staged recovery (darker): For a more drawn-out recovery process, rather than completely eliminating Compelling Flaws with a success, simply downgrade them to regular Flaws, which must then be rolled for again to eliminate them completely.

Experience Points: As long as a character possesses at least one Compelling Flaw, all experience point expenditures double.

Style Points: As long as a character possesses at least one Compelling Flaw, the character may gain no Style points from playing other regular Flaws, or adhering to his Motivation, though the latter will still grant a treatment/ recovery roll bonus.

Created by Silverback. Last Modification: Sunday 04 of January, 2009 13:50:43 MST by Silverback.