Damage. It is at the heart of rules for Dungeons & Dragons. Hit points are god. This is an excerpt from my forthcoming monograph, The Harrowed that expands on the variant rules for sanity, madness and lingering injuries in Chapter 9 of the Dungeon Master's Guide.
They are inspired by my favourite computer game, Darkest Dungeon. If you haven't played it, check it out. The rules for stress are particularly well thought out, adding an additional time pressure to complete adventures.
This variant is for gritty or low fantasy campaigns where adventuring life is not just hard on the body, but risks sanity as well.
When you encounter a stressful event you must make a Charisma saving throw or suffer psychic damage. If you fail your saving throw by 5 or less you also become Frightened for 1 minute. The DC and amount of damage depends on the difficulty of the stress: whether it is disturbing, shocking, horrifying or monstrous as per the Stressful Events table.
In low fantasy campaigns, where monsters (at least the non-human kind) are rare or legendary, encountering such creatures could be also a stressful event. See the following table:
You get advantage on the Charisma saving throw if you have encountered this type of magical creature before. If you fail your saving throw by 5 or less you also become Frightened for 1 minute.
|Disturbing||15||1d4||Defeat in combat, witnessing a stranger take a severe wound or die, being trapped underground without light.|
|Shocking||17||1d8||Witnessing an ally take a severe wound or die, being betrayed by an ally, witnessing torture.|
|Horrifying||20||1d10||Witnessing an ally transform into a monstrous creature, a premonition of the end of the world, being tortured.|
|Monstrous||25||1d20||Encountering a god, being transported to hell, transforming into a monstrous creature.|
Variant: Lingering Psychic Injuries
This variant gives an additional table for lingering injuries for psychic damage. Continue to roll on the old Lingering Injuries table for non-psychic damage.
|1||Mania. You have advantage on all attack rolls. When you make an attack roll, attack rolls against you have advantage until your next turn.|
|2||Panic. You have disadvantage on all Dexterity attack rolls, saving throws and ability checks.|
|3||Traumatised. Your exhaustion is always one level higher.|
|4||Despair. You, and any creature within 30 feet of you who can hear and understand you, have disadvantage on Charisma saving throws.|
|5-7||Fearful. You, and any creature within 30 feet of you who can hear and understand you, have disadvantage on Wisdom saving throws.|
|8-10||Paranoid. You gain the flaw
Trust no-one, they are out to get me.Your speed is halved and you have disadvantage on Wisdom ability checks and saving throws.
|11-13||Irrational. You gain a delusion as a new flaw. You have disadvantage on all Intelligence saving throws and ability checks. Roll on the delusions table, or come up with your own.|
|14-16||Selfish. You gain the flaw
I cannot stop talking about myself.You have disadvantage on all Charisma ability checks.
|17-20||Tick. You gain a odd as a new personality trait. Roll on the ticks table or create your own tick.|
|1||I constantly grind my teeth.|
|2||I flinch whenever anyone is about to touch me.|
|3||My left eye constantly twitches.|
|4||I get uncontrollable shakes.|
|1||I have been chosen by the gods to save the world from doom.|
|2||I am worthless and deserve to die.|
|3||Demons speak to me in my dreams and tell me terrible truths.|
|4||I am convinced I'm dying of a fatal disease.|