diff --git a/tests/unit/entity-instances.test.ts b/tests/unit/entity-instances.test.ts
new file mode 100644
index 00000000..fa7b4403
--- /dev/null
+++ b/tests/unit/entity-instances.test.ts
@@ -0,0 +1,71 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  DEFAULT_INTERACTABLE_PROMPT,
+  DEFAULT_SOUND_EMITTER_GAIN,
+  DEFAULT_SOUND_EMITTER_RADIUS,
+  DEFAULT_TRIGGER_VOLUME_SIZE,
+  createDefaultEntityInstance,
+  createInteractableEntity,
+  getEntityRegistryEntry
+} from "../../src/entities/entity-instances";
+
+describe("entity registry defaults", () => {
+  it("creates explicit typed defaults for each supported entity kind", () => {
+    expect(createDefaultEntityInstance("playerStart")).toMatchObject({
+      kind: "playerStart",
+      position: { x: 0, y: 0, z: 0 },
+      yawDegrees: 0
+    });
+
+    expect(createDefaultEntityInstance("soundEmitter")).toMatchObject({
+      kind: "soundEmitter",
+      position: { x: 0, y: 0, z: 0 },
+      radius: DEFAULT_SOUND_EMITTER_RADIUS,
+      gain: DEFAULT_SOUND_EMITTER_GAIN,
+      autoplay: false,
+      loop: false
+    });
+
+    expect(createDefaultEntityInstance("triggerVolume")).toMatchObject({
+      kind: "triggerVolume",
+      position: { x: 0, y: 0, z: 0 },
+      size: DEFAULT_TRIGGER_VOLUME_SIZE,
+      triggerOnEnter: true,
+      triggerOnExit: false
+    });
+
+    expect(createDefaultEntityInstance("teleportTarget")).toMatchObject({
+      kind: "teleportTarget",
+      position: { x: 0, y: 0, z: 0 },
+      yawDegrees: 0
+    });
+
+    expect(createDefaultEntityInstance("interactable")).toMatchObject({
+      kind: "interactable",
+      position: { x: 0, y: 0, z: 0 },
+      radius: 1.5,
+      prompt: DEFAULT_INTERACTABLE_PROMPT,
+      enabled: true
+    });
+  });
+
+  it("keeps entity metadata and prompt validation explicit", () => {
+    expect(getEntityRegistryEntry("triggerVolume")).toMatchObject({
+      kind: "triggerVolume",
+      label: "Trigger Volume"
+    });
+
+    expect(
+      createInteractableEntity({
+        prompt: "  Open  "
+      }).prompt
+    ).toBe("Open");
+
+    expect(() =>
+      createInteractableEntity({
+        prompt: "   "
+      })
+    ).toThrow("Interactable prompt must be non-empty.");
+  });
+});