One Actor Type's Rule on a Shared Stat

Some Environments are on every Actor. The usual one is Default: it holds Health, Dead, TeamNo, and the SigSep lists those Stats read their rules from — the Counter Effects, Reflectors and Modifiers that run when Health changes.

Now the player gets Thorns: "when I take damage, the attacker takes 5". That is a Counter Effect on Health. Where should it go?

Don't define it in the shared Environment

If the Counter Effect is added to the Default Environment's ReceivingHealthCounterEffects list, every Actor that uses Default gets Thorns — every mob, every destructible. Worse, if the rule checks a Stat only the player has (a ThornsUnlocked switch, a ThornsDamage amount), every hit on an Actor without it logs a warning.

A shared Environment should hold what every Actor shares. Rules that belong to one Actor type are linked in at spawn instead.

Link it in

1. Define the rule in the owner's Environment. Create the Counter Effect as a standalone Stat (its own Stat Id and a plain Stat Key) in the Player Environment, next to the Player's other Stats.

2. Create a Linker Effect that inserts it into the shared list:

   Field	Value
   Effect	Linker Effect, Processor Id Linker, Apply Type Temporary, Modifier Type Managed By Code
   Target Stat	the shared list — ReceivingHealthCounterEffects(SigSep) in Default
   Injector Stat	the Player's Thorns Stat (read from the Source)
   Linker	Insert Stat To SigSep Stat — _EffectPack for Counter / Intervener / State Based lists, _Float for Reflector / Modifier lists, _Int for Director lists
   SigSep Stat Order	a number not yet used on that list

3. Put the Linker Effect into the owner's linker Effect Bundle. An Effect Bundle applies its pack to its own Actor when the Actor starts and removes it when the Actor is disposed — so every Player gets Thorns inserted into its own Health list, and mobs keep the shared list as it is.

The shared list never changes as an asset; each Player's runtime copy gains one more entry.

SigSep Stat Orders must be unique on the list

The list is keyed by its inner Stats, ordered by SigSep Stat Order. That order must not be used by the list's own inner Stats nor by any other Linker inserting into the same list. A duplicate order drops the Stat when the Actor spawns, and the mechanic silently never runs.

Before picking one, look at the list's own Stat Orders and at every Linker that targets it. The Linker Effect's Injection Order is a different number (its slot on the Target Stat) and may repeat.

When you don't need this

• Every Actor should have the rule (all Actors die at 0 Health): define it in the shared list directly.
• The rule only reads a value another Actor type never has a reason to change (a DamageReduction Modifier the player owns): it can stay a Stat in the owner's Environment, read through a relation that resolves on the owner — see Which Actor Resolves a Relation.
• The whole Environment is the owner's (a Player Environment only Players have): add the rule to that Environment's own lists; nothing else sees them.