Rumor System

Information mutates as it travels between NPCs.

Overview

Player kills the boss
    ↓
NPC1: "I heard someone slew a dragon?"
    ↓
NPC2: "Actually, I heard it was a wizard."
    ↓
NPC3: "The demon king is dead, they say."

Component

RumorSystem — MonoBehaviour.

Field	Type	Default	Description
MutationChance	float	0.3f	Probability of mutation (0~1)
MutationSuffixes	List<string>	4 defaults	Sentences appended on mutation
ActiveRumors	List<RumorData>	—	Currently active rumors

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API

SpreadRumor

void SpreadRumor(string fact, string sourceNpcId)

rumorSystem.SpreadRumor("Someone slew a dragon", sourceNpcId: "player");

PassRumor

RumorData PassRumor(RumorData rumor, string receivingNpcId)

Content mutates with MutationChance probability.

Events

event Action<RumorData> OnRumorSpread          // When rumor first created
event Action<RumorData, string> OnRumorPassed  // Each time rumor is passed

---

RumorData

public class RumorData
{
    public string OriginalFact;
    public string CurrentVersion;
    public int HopCount;
    public float SpreadAt;
    public string SourceNpcId;
}

---

Example

using NpcMentality;

public class RumorDemo : MonoBehaviour
{
    public RumorSystem rumorSystem;
    public string[] npcIds = { "blacksmith", "innkeeper", "farmer", "guard" };

    private void Start()
    {
        rumorSystem.OnRumorPassed += (r, npcId) =>
            Debug.Log($"[{npcId}] hop {r.HopCount}: \"{r.CurrentVersion}\"");
    }

    public void OnPlayerKillsDragon()
    {
        rumorSystem.SpreadRumor("Someone slew a dragon", "player");
        StartCoroutine(SpreadToVillage());
    }

    private System.Collections.IEnumerator SpreadToVillage()
    {
        var rumor = rumorSystem.ActiveRumors[^1];
        foreach (string npcId in npcIds)
        {
            yield return new WaitForSeconds(2f);
            rumorSystem.PassRumor(rumor, npcId);
        }
    }
}

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Tips

• MutationChance = 0f — facts spread without any mutation.
• MutationChance = 1f — every pass guarantees a mutation.
• Combine with RelationshipContagion to spread both content and emotion through the village simultaneously.
• Use HopCount to implement "this rumor is unreliable" UI.