Necromantic Compound Interest

What this demonstrates

Why it works

The rule ignores original placements and watches only dynamically created undead. When one of those creatures becomes active while dead, SSS rolls a chance to create up to two skeletons around it. Each child is itself a generated object, so after it eventually dies it can satisfy the same rule.

This is population dynamics through declarative YAML. once: true limits each dead generated object to one successful application across save/load; it does not impose one global limit on the family tree.

The catch

once: true records a successful application, not a failed roll. If the spawn pool misses, the corpse remains eligible on a later activation.
Given enough revisits, every eligible dead generated undead eventually reproduces. A successful count roll samples uniformly from 1–2, so eventual offspring are 50% one child and 50% two children: expected offspring 1.5 per reproducing corpse. This is not a subcritical branching process; skeleton singularity is the mathematical destiny of the module if the descendants keep dying.
SSS has no reproduction timer here. The rule runs when the dead generated object becomes active and SSS processes it.
Created objects become ordinary saved world objects. Removing the YAML does not automatically remove the population it created.
creature_type: undead already restricts the rule to Creature records; NPCs are not included by this condition.

Complete YAML

The source fixture is Examples/InstanceModifier_NecromanticCompoundInterest.yaml.

log_name: Necromantic Compound Interest
priority: balance

instances:
  - conditions:
      - generated_object: true
      - is_dead: true
      - creature_type: undead
    once: true
    actions:
      - create:
          skeleton:
            count:
              max: 2
            chance: 0.35
            position:
              x: { min: -96, max: 96 }
              y: { min: -96, max: 96 }