Stress accumulation

Owns a per-agent stress value with slow decay and a ladder of levels. Each experience adds or removes an amount scaled by personality, and the value relaxes toward zero only slowly, so stress is an integral of history rather than a snapshot of current conditions. Crossing a level triggers a break event, a coping trait, a lasting change in behavior, or death at the extreme. Dwarf Fortress keeps a hidden stress value from -1,000,000 to +1,000,000 with effects from +10,000, +25,000, and +50,000: emotions add or subtract stress, facets such as bravery, stress vulnerability, and anxiety scale it, long-term memories keep adding to it, and high stress leads to tantrums, depression, obliviousness, or insanity. Crusader Kings III adds stress when a character acts against its personality traits, fires mental-break events as stress levels are crossed, lets breaks at level 2 or higher change traits, and can kill at extreme stress, all without a mood meter. It differs from mood-breakdown, whose mood is a near-instant sum of current modifiers, and from memories-thoughts, which owns the event entries that can feed it.

The player manages a slow-burning account of bad experiences rather than a moment-to-moment mood: a character can look fine while carrying stress from months ago. In Crusader Kings III this makes roleplay a resource decision, since acting against a character's traits costs stress that must later be shed; in Dwarf Fortress a fortress's past tragedies become a hidden debt that comes due.

• stress per event type and the personality scaling applied to it
• decay rate toward zero and whether relief needs active coping (feasts, hobbies, vices)
• level thresholds and what each level triggers
• break catalog: tantrums, coping traits, personality change, death
• visibility of the value, hidden as in Dwarf Fortress or shown as in Crusader Kings III

• Hidden stress makes breakdowns look random, since the cause may be months old.
• Slow decay plus frequent stressors leaves a population chronically stressed after one disaster, with no recovery path.
• Cheap relief actions such as a feast or a vice reduce stress management to a periodic chore.
• Lethal stress at the top of the ladder can end a character or dynasty through bookkeeping rather than drama.

• A shared tragedy stresses many agents at once, so breaks cluster weeks or months after the event.
• Breaks generate new stressors for witnesses, a reinforcing cascade, as in Dwarf Fortress tantrum spirals.
• Coping traits acquired through breaks permanently change characters, turning stress history into identity.

• Does showing the stress value make breaks feel fair at the cost of drama, or can partial signals give warning without a meter?
• Can language-model agents express accumulated stress in dialogue and behavior before a threshold break, so players see it building?