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Modulate attack weights with societas

Wire societas_encounter::SocietasRelationshipSource into an encounter scene so attack weights reflect live relationship state. Trust dampens attacks; fear amplifies them.

Learning objective: add societas-relationship modulation to an existing encounter scene with one new dependency, one resolver registration, and one weight-computation call per attack edge.

Prerequisites​

  • The library installed and a working scene from Build your first scene.
  • The societas-encounter crate available as a path-dep or registry dep (with the argumentation feature).

Step 1: Add the dep​

[dependencies]
societas-encounter = { version = "0.1", features = ["argumentation"] }
societas-core = "0.1"
societas-relations = "0.1"
societas-memory = "0.1"   # or any other SocialStore impl

Step 2: Build the resolver​

Map your scene's actor names to societas EntityIds.

use societas_core::EntityId;
use societas_encounter::names::StaticNameResolver;

let mut resolver = StaticNameResolver::new();
resolver.add("alice", EntityId::from_u64(1));
resolver.add("bob", EntityId::from_u64(2));

StaticNameResolver::add panics on names that collide with affordance role-binding slots ("self", "target", "subject", "initiator", "aggressor", "actor", "recipient", "witness"). Use character names that don't conflict.

Step 3: Seed relationship state​

Attack weights derive from five dimensions: trust, fear, respect, attraction, friendship. Seed any subset — unseeded dimensions sit at zero (neutral).

use societas_core::{ModifierSource, Tick};
use societas_memory::MemStore;
use societas_relations::{Dimension, RelationshipRegistry};

let mut store = MemStore::new();
let registry = RelationshipRegistry::new();

// Bob trusts Alice → Bob's attack on Alice's claim is dampened.
registry.add_modifier(
    &mut store,
    EntityId::from_u64(2),  // bob
    EntityId::from_u64(1),  // alice
    Dimension::Trust,
    1.0,                    // magnitude in [-1, 1]
    0.0,                    // decay rate; 0.0 = permanent
    ModifierSource::Personality,
    Tick(0),
);

Step 4: Build the source​

use societas_encounter::SocietasRelationshipSource;

let source = SocietasRelationshipSource::new(
    &registry,
    &store,
    &resolver,
    state.actors_by_argument(),
    Tick(0),
);

Tick is owned and fixed at construction. To advance time mid-scene, build a fresh source.

Step 5: Compute and seed weights​

For each attack edge in your framework, ask the source for a weight, then wire it via add_weighted_attack:

use argumentation_weighted::WeightSource;

let w = source.weight_for(&bob_id, &alice_id).unwrap();
state.add_weighted_attack(&bob_id, &alice_id, w)?;

weight_for always returns Some(_) — unresolved actors or unseeded arguments fall back to BASELINE_WEIGHT (0.5).

How the weight gets computed​

For one attacker–target actor pair:

weight = clamp(
  BASELINE_WEIGHT
    + TRUST_COEF       * trust       // -0.15 — high trust dampens
    + FEAR_COEF        * fear        // +0.25 — high fear amplifies
    + RESPECT_COEF     * respect     // -0.05
    + ATTRACTION_COEF  * attraction  // -0.05
    + FRIENDSHIP_COEF  * friendship, // -0.10
  0.0, 1.0,
)

Multi-actor arguments (when one ArgumentId was asserted by two or more actors) average the per-pair weights across the (attacker × target) Cartesian product.

Verify​

Construct the same scene twice — once with high trust, once with high fear — and check the weights:

assert!(w_trust < 0.5);   // trust dampens below baseline
assert!(w_fear  > 0.5);   // fear amplifies above baseline

For an end-to-end credulous-acceptance flip, see the integration test in societas-encounter/tests/relationship_source.rs.

When NOT to use this​

  • Static scenes where the dramatic outcome should be deterministic regardless of relationship state — wire weights directly via add_weighted_attack(... w_hardcoded) instead.
  • Scenes without scheme-backed arguments — the source resolves ArgumentId → actors via actors_by_argument(), which only knows about scheme instances seeded via add_scheme_instance / add_scheme_instance_for_affordance.