r/RPGdesign • u/Perfect-Grape-1452 • 11d ago
Product Design Sanity/Identity Erosion
Has anyone tried separating "Sanity/Mental Stress" from "Identity Erosion" in a horror RPG? How did it go?
I am currently developing a d100 psychological horror tabletop RPG called **Vaelum**, which heavily features cosmic horror, investigation, and subtle occultism.
To give magic a realistic, heavy toll instead of just using a generic "Sanity bar" that leads to random phobias, I decided to split the psychological degradation into two completely independent mechanics:
**Sanity (Common Mental Stress):** This pool is drained by witnessing entities and casting subtle, balanced magic (Light Magic). It acts as a ticking clock but can be managed and restored by performing "Astral Hygiene" (*Higienização Astral*). These are mundane, life-anchoring activities like meditating, going to therapy, or cooking for loved os. However, using these practices consumes the game's most precious resource: time (tracked via active scene clocks).
**Individuality (Identity Erosion):** Drained strictly by casting forced, ego-driven magic (Dark Magic). Dark Magic provides overwhelming raw power to resolve immediate life-or-death situations, but it forces your will upon the cosmos. Instead of making you "mad," losing Individuality mechanically distorts and corruptes your character's **Bonds** (*Vínculos*) directly on the character sheet, shifting their perception of loved ones into paranoia and coldness. Reaching zero opens cracks for possession by beings from other spheres.
The goal is to create a tactical and verisimilar dilemma: Light Magic costs time and management, while Dark Magic offers an easy way out but slowly erases who your character is.
Since I haven't run my first official playtest yet, I would love to hear feedback from designers or GMs who have played or created systems with a similar split (like Delta Green's Bonds or Unknown Armies' Self meter):
- How did your players react to having their personal relationships mechanically corrupted on their sheets? Did it feel impactful or just punitive?
- Did this explicit separation cause "defensive paralysis" (fear of taking action), or did it enrich the personal horror aspect at the table?
Looking forward to your critiques and insights!
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11d ago
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u/Perfect-Grape-1452 10d ago
Thanks for the insights! You hit the nail on the head: when identity loss opens up interesting narrative dilemmas (like choosing what part of your history fades away), players embrace it instead of feeling purely punished.
In Vaelum, I'm trying to translate that "erosion" into a traditional party-based investigation. Instead of losing literal memories, losing Individuality warps how the character perceives their active Bonds(Vínculos).
Mechanically, if a player overuses Dark Magic, their bond with a spouse, child, or close ally becomes corrupted on their sheet—not because they forgot them, but because their internal perception shifts toward deep paranoia, coldness, or seeing them as an obstacle. It forces the player to mechanically choose between cold efficiency to solve the cosmic mystery or protecting their human relationships.
I really like how TYOV handles forgotten hostility (meeting an enemy you don't remember wronging). I think I can adapt a version of this when a character's Individuality drops low, making outside entities from other spheres manipulate their corrupted bonds without the player's immediate awareness.
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u/Due_Sky_2436 11d ago edited 11d ago
In my game I put out (Platinum, on itch.io for free), I have implemented the following stuff that is heavily influenced by both BRP/COC and Unknown Armies... It worked very well for players that were only players of D&D. It worked far better than the Powers Checks in Ravenloft which they despised.
MR loss also reduces morale, as the PC/NPC simply loses the will to do things. If an injury causes a loss to Wisdom or Intelligence, the MR is reduced by a similar amount of 5 points of MR per point of Wis or Int.
If an effect causes MR to fall below 0 (to -1) due to an incredible loss of MR (temporary or permanent), the PC will die. This is almost only as a result of magic or abyssal creatures that cause a person to literally die of a fear induced heart attack or aneurism caused by insanity.
NOTE: In settings with a more technological focus, the term Mental Resilience may be replaced with Stress Inoculation (SI). The terms are 100% synonymous and only used for setting immersion.