the hero must make an intelligence saving throw to perform any sustained/monotonous task. consult the following chart to determine the outcome of the roll:

• natural 1: the hero is completely unable to focus and may not attempt the task again until after taking a long rest.
• 1–9: the hero is unable to focus and cannot attempt the task again until after a short rest.
• 10–19: the hero is able to perform the task. the outcome of the roll determines how quickly they’re able to make progress on it.
• 20+: the hero is considered hyperfocused until the task is complete or they succeed a wisdom saving throw against being hyperfocused (DC 10 or 15 at DM discretion). If the hero is hyperfocused on a task during a short rest, they do not gain the benefits of taking the rest. hyperfocused individuals can perform a task faster than normal and have advantage on checks related to the relevant task.
• natural 20: the hero hyperfocuses on the task without any of the penalties typically invoked by hyperfocus and are able to come to a stopping point without making a save.

adhd heroes also have a +1 bonus to passive perception.

when spending prolonged time in direct sunlight, make a constitution saving throw against sunburn. on a fail, the character takes 1 point of nonlethal damage for each hour in the sun. heroes who dress appropriately to cover their skin do not have to make the save.

Heroes with albinism also have a -1 penalty to passive perception and suffer disadvantage on perception checks made in bright light or saving throws against spells and abilities that utilize bright light (ex: sunbeam) without the use of protective eyegear. Albino heroes have at least low-light vision regardless of race and have advantage on perception checks made at night. 

in high pressure situations (as determined by the dm), make a wisdom saving throw with a situation-dependent DC. on a fail, the character has disadvantage on ability checks. The severity of the character’s anxiety should be rated on a scale of 1–5 during character creation, and that number is added to the DC of all anxiety-based wisdom saving throws. (optional: critical fail causes the hero to be incapacitated until the end of your next turn or until a save ends (you/your dm’s choice).)

the hero has disadvantage on all charisma checks. (joke/optional: … except on charisma checks in the stead of another character with anxiety, at which point the disadvantage cancels out.)

penalties are dependent on affected joints and severity of the arthritis (for more severe symptoms, include the optional penalties): . choose from the following penalties to affected joints:

• wrists: the first use of an object in a round costs one use an object action in lieu of a free action. further use an object actions cost a bonus action. (optional: disadvantage on slight of hand checks)
• knees: -5 foot penalty to move speed in initiative. (optional: disadvantage on athletics checks)
• ankles: takes full movement to stand from being prone and the hero has disadvantage on dexterity saving throws to keep from being knocked prone. (optional: disadvantage on acrobatics checks)

at character creation, choose at least one trigger for your hero’s asthma:

• physical exertion/exercise: the hero must make a constitution saving throw in order to dash in or outside of combat. If not, the hero has disadvantage on all attack rolls and ability checks. medication gives the hero advantage on the constitution saving throw to prevent or end the effect.
• allergens/irritants: the hero has disadvantage on saving throws against gaseous effects. the hero also must make a constitution saving throw in dusty, smoky, moldy, or otherwise heavily irritant-filled rooms/locations, otherwise they have disadvantage on all ability checks until they succeed on a save. medication gives the hero advantage on the constitution saving throw to prevent or end the effect.
• night asthma: roll a constitution saving throw at the beginning of a long rest. on a fail, the hero does not get a good night’s sleep and takes one level of exhaustion. medication gives the hero advantage on the constitution saving throw to prevent the effect. (optional: at character creation, roll a d%. on a 60% or higher, the hero deals with night asthma effects as a part of their condition.)

should the hero go five rounds without saving from the effect, it ends, and the hero is given one level of exhaustion.

the hero has a -1 penalty to all perception checks and a -2 penalty to perception checks related to hearing.

Utilize the stress mechanic as a basis for the disorder with penalties that apply in the same way. At 5 points of stress, the hero has a meltdown and can only stim and make wisdom saves. stimming will give the hero advantage on their next save.

at the start of each long rest, make a wisdom saving throw. on a success, stress is reduced by 1 point. on a fail, stress is maintained they failed by a number of points less than or equal to their proficiency modifier. Any less than that, and they gain another point of stress. stress can also be reduced by spending a short rest stimming or doing other self-care techniques, which will prompt a wisdom-saving throw that can only either maintain or reduce stress, not increase it. a natural 20 removes two stress points. a natural 1 adds two. stimming or other self-care activities done before the long-rest wisdom-saving throw will give the hero advantage.

additionally, choose two items from the following traits as suits your character (other traits can be invented and added at dm discretion):

• difficulty with tonal/volume/facial expression modulation: disadvantage on charisma checks with characters you haven’t interacted with before.
• sensory processing disorder: the hero may utilize advantage on perception checks but must make a wisdom saving throw to keep from taking one point of stress. the hero must also make wisdom saving throws against overwhelming sensory stimulation (DM discretion) or add another stress point.
• special interest: choose a subject (subject to DM approval). your hero has advantage on all knowledge checks related to that subject.
• difficulty reading people: the hero has disadvantage on insight checks against other sentient beings.
• alexithymia: the hero has disadvantage on charisma saving throws whenever they have 1+ points of stress.

Roll a d% and a d10 and consult the following chart (these numbers may need to be adjusted):

• 1%–40%: the hero is considered to be in a depressive episode. consult the mechanics for depression to determine penalties involved.
• 41%-60%: the hero is fairly balanced and neither manic nor depressive. no penalties are incurred.
• 61%–100%: the hero is considered manic. manic heroes cannot be surprised and have advantage on initiative rolls. manic heroes must make a wisdom save at the end of every long rest. on a fail, the following occurs: heroes have disadvantage on wisdom saving throws, intelligence saving throws, and concentration checks.

At the end of a long rest, make a wisdom saving throw. When manic or depressive, a failed save results in the hero staying manic or depressive. When stable, a successful save results in them staying stable. Should the hero succeed their wisdom saving throw while manic or depressive or fail their wisdom saving throw while stable, they must again reroll the d% die to determine their new state.

the hero has disadvantage on all perception checks that relate to vision. at the discretion of the dm, they may have advantage on checks that relate primarily to other senses. Characters who start the game blind may take braille as a free language.

alternate ruling: the hero has a penalty to perception that increases with the level of impairment, from a penalty of -1 to -5. the hero does not have disadvantage on any rolls as a result of their blindness.

(optional: heroes born blind may take the Alert feat at the beginning of the campaign. heroes blinded later in life must still take it via feat purchase.)

consult the following chart to determine the penalty based on where most of the scarring is:

• legs: the hero has a -1 penalty to move speed while in initiative and has disadvantage on dexterity saving throws.
• arms/hands: the hero has disadvantage on all ability checks made with tools.
• chest: character has disadvantage on constitution saving throws to save against gaseous effects and on endurance checks. they must make a constitution check in order to dash.

roll a d20 at the end of a long rest. on a roll of 3 or lower, take one level of fatigue. this number can be adjusted for the severity of the chronic fatigue to increase or decrease the odds of being penalized. (optional: critical failure adds two levels of fatigue.)

each day, roll 1d10 to determine the hero’s pain level for the day, then make a constitution saving throw. The DC should be determined based on the severity of the pain the hero is trying to manage.

• 1–3: the hero has mild pain, causing stiffness and discomfort. They have disadvantage on dexterity and dexterity-based checks. heroes also have disadvantage on initiative rolls.
• 4–6: the hero is dealing with moderate pain, making it difficult to perform most physical activity. in addition to the above, they have disadvantage on all strength and strength-based checks.
• 7–9: the hero is in severe pain and is having trouble focusing on anything other than their pain. in addition to the above, heroes have disadvantage on all intelligence and intelligence-based checks, as well as disadvantage on all saving throws.
• 10: the hero is in so much pain that they are unable to function. all ability checks and saving throws should be made at disadvantage, and the hero’s speed is halved.

(optional: the hero has advantage on concentration checks because they’re used to managing pain.)

The inhibitions put in place by the hero’s level of pain can be mitigated with healing, which will trigger a second constitution saving throw.

during character creation, roll a d% twice and take either number (or average them), then subtract your total constitution score from the result. this is your sickness score. at the beginning of a long rest, roll a d%. if the result is lower than the sickness score, the food you ate during the day prior has upset your chron’s, and you need to make a constitution saving throw. on a fail, the hero has disadvantage on constitution and dexterity saving throws, including the save against being sick the following evening. medication/potions to ease the effects of this disease grant advantage on the saving throw against being sick.

the hero has advantage on perception checks that relate to finding a hidden or obscured object, as well as on perception checks that relate to finding stealthed individuals. additionally, the hero has disadvantage on all perception checks in low light or darker.

the hero has disadvantage on all perception checks that primarily relate to hearing. they have disadvantage on all perception checks in light levels lower than what they can see clearly in, even with campfire or torchlight. if the character doesn’t speak common, they have disadvantage on charisma checks with someone who can’t sign (negated if they have an interpreter).

deaf characters may choose either common or sign language as their starting language and may take the other as one of their additional languages. Being able to speak common includes the ability to read lips at any visible distance without the use of a feat and negates the aforementioned penalty to charisma checks. not being able to see an individual’s lips while speaking negates the ability to understand them without an interpreter or other means.

at the end of each long rest, make a wisdom saving throw. on a fail, the hero has disadvantage on initiative rolls and saving throws, and they may not take opportunity attacks. the disadvantage on saving throws includes the wisdom saving throw to determine their ability to perform well the following day. (death cw/optional: on a critical failure, the hero has disadvantage on death saving throws until they complete their next long rest.)

the hero must make an intelligence saving throw or has disadvantage on persuasion checks to haggle and barter with currency and on checks related to numbers in any way (ex: numeric puzzles).

the hero makes an intelligence saving throw to read any written text. on a fail, it takes twice as long to read. (optional: on a critical failure the hero ends up with a migraine.)

when writing a letter, the hero must make a charisma saving throw. on a fail, the letter’s ability to perform its function is diminished (ex: a persuasive letter no longer being able to convince the reader, an apology letter not impressing the addressee, etc.)

for dyslexic characters affected by auditory processing disorder, add the ruleset for APD above.

whenever the hero encounters spells, abilities, or other effects that cause bright or flashing lights (prismatic spray, sunbeam, fireball, lightning, etc.), the hero must make a constitution saving throw or be knocked prone. The hero is prone until they are able to save from the condition and may not take other actions until a success.

when the hero is bloodied, they suffer an additional 1d6 bleed damage per round until they are no longer bloodied.

before a long rest, make a constitution or wisdom saving throw. on a failed save, the user gains one point of fatigue. on a critical failure, the user gains one point of fatigue and does not regain the use of their powers for the next day.

the hero takes a permanent -2 penalty to their total dexterity score (characters born with a missing limb will calculate their scores without factoring in the missing limb and then subtract 2. this is to avoid minmaxing). characters who have had a limb amputated have disadvantage on dexterity-related checks and saving throws as they pertain to the missing limb. heroes born with missing limbs do not suffer disadvantage on ability checks or saving throws. any character who take the time to acquire and familiarize themselves with the use of a prosthetic may either negate the imposed disadvantage or the -2 to dexterity. characters may design, invent, or commission unique adaptive devices that grant specific skill bonuses at the discretion of their dm.

whenever the hero must make a charisma or charisma-based check, they must first make a wisdom saving throw. if they fail, they must make the check at disadvantage. a critical failure means the hero is completely nonverbal.

at character creation, determine the body’s physical stats (str., con., and dex.). These stats are concrete and cannot be changed. for each headmate in the system, the remaining three statistics (int., wis., and cha.) may all vary. in the case of point buy, the numbers may be rearranged but not exceed the total point allocation value, in the case of rolled stats, roll them per the requirements of your dm. this may be done for every headmate, including those who emerge later.

the host’s class determines the starting class of the body, and the classes of any headmates can be obtained by multiclassing. headmates may take any class that can be learned and doesn’t require the hero to be born with that ability (ex: sorcerers), and the player can select which headmate takes a level in their chosen class upon leveling up.

the player must call who is fronting to the dm whenever there’s a switch. players should not exploit the presence of multiple headmates to switch in and out and perform skill and ability checks based on which headmate has the best relevant score. use discretion and consult with the dm with regards to where the limits are. it costs an entire standard action to willingly switch who is fronting within the system.

(optional rule: whenever a new headmate appears, allocate the strength/frequency that they front to a percentage. after completing a long or short rest, roll a d%, and the result determines who is fronting going forward.)

At the end of a long rest, make a constitution saving throw. on a failed save, the hero has disadvantage on initiative checks and cannot make opportunity attacks until the end of their next long rest due to daytime drowsiness. on a critical failure, the hero gains no meaningful rest over the course of the night and was struck by sleep paralysis. take one level of exhaustion.

During a short rest, narcoleptic heroes may spend the short rest napping in an attempt to combat their daytime drowsiness. At the end of the short rest, they may make another constitution saving throw against their drowsiness.

at character creation, roll a d%. if the roll is 70% or lower, the character has cataplexy as a symptom of their narcolepsy. when surprised or put under a fear effect, cataplexic heroes must make a constitution saving throw or be knocked prone.

This mechanic is meant to be used in conjunction with the stress system at the bottom of this post.

hypersensitivity: the hero has advantage on insight checks.

rejection-sensitive dysphoria: whenever the hero has any points in stress, they assume all negative emotion is directed at them. whenever the hero has stress, at the end of each short rest, they must make a wisdom saving throw. on a fail, the hero has disadvantage on wisdom and charisma saving throws until their next short rest.

make a list of things related to your hero’s trauma or trauma triggers. when they come up in game, have the hero make a wisdom saving throw every round until the trigger is gone or has subsided. Add one point of stress for each failed saving throw.

On a count of 3 stress points, the character is considered to be under a fear effect related to whatever caused the trauma trigger to surface. continue to make wisdom saving throws until the number of stress points falls below 3. on a score of 5 stress points or more, the hero is incapacitated and can only save from the effect.

a natural 20 causes the hero to automatically lose all stress points and makes them immune to the ptsd effect until the end of the encounter, whereas a natural one automatically brings them to 5 stress points. stress points are reset after a long rest. (optional: make a wisdom saving throw at the end of a long rest to determine if/how many stress points are removed.)

at creation, the hero can select which elements and symptoms of schizophrenia affect their hero.

visual hallucinations: at the end of each long rest, the hero must make a wisdom saving throw. consult the following chart to determine the results:

• natural 1: the hero takes a -5 penalty to perception checks and must make another wisdom saving throw at the start of each combat or else has disadvantage on all attack rolls.
• 1-5: the hero takes a -4 penalty to perception checks.
• 6-10: the hero takes a -3 penalty to perception checks.
• 11-15: the hero takes a -2 penalty to perception checks.
• 16-19: the hero takes a -1 penalty to perception checks.
• 20+: the hero incurs no penalty to perception for the day.

auditory hallucinations with intrusive thoughts: at the end of each long rest, the hero must make a wisdom saving throw. on a fail, the hero must make a charisma saving throw at the start of each short rest. on a fail, the hero spends the entirety of the short rest working through the episode and does not gain any of the benefits of the short rest.

paranoia: at the end of each short rest, make a wisdom saving throw. on a fail, the hero must behave in accordance with being paranoid and suspicious. the hero cannot be surprised and has disadvantage on wisdom and charisma saving throws.

stress is a function that applies to multiple disabilities above and many others not included on this list, particularly mental illnesses that are heavily roleplay-based, such as personality disorders. stress is incurred at dm discretion based on story events. if a character has been negatively impacted by plot developments or character interactions, the hero must roll a wisdom saving throw or else be penalized with one point of stress.

(optional: at the beginning of every long rest during a difficult mission, each hero must roll a wisdom saving throw to determine how well they’re coping with the event.)

consult the following table to determine penalties for various stress levels.

• 1 point: the hero incurs no penalties, but following stress checks have a higher dc.
• 2 points: the hero must roll a d4 at each short rest to determine a penalty that will affect them until their next short rest. see below for possible effects.
• 3 points: the hero has disadvantage on all charisma-based checks as well as all above penalties. when surprised, this hero is affected for two rounds instead of one.
• 4 points: this hero has disadvantage on all ability checks as well as all above penalties. this hero must make a wisdom save each night or else not benefit from a full night’s rest.
• 5 points: this hero is completely unable to function due to stress. they cannot perform any activities not as a reaction to stress until steps have been taken to reduce their stress score.

d4 effect rules will cause the hero to dissociate, derealize, or depersonalize as follows:

• 1: the hero has dissociated. they have disadvantage on all acrobatics and stealth checks.
• 2: the hero has depersonalized. they have disadvantage on all persuasion and deception checks.
• 3: the hero has derealized. they have disadvantage on all investigation and perception checks.
• 4: no effect.

heroes may reduce their stress levels by partaking in stress-relief or self-care activities that allow them to make a second wisdom-saving throw to attempt to lower their stress levels. these rolls can be done without risk of incurring further stress. high rolls on stress wisdom saving throws can also reduce stress levels. a nat1 will add two points of stress, where a nat20 will clear all stress away.