diff --git a/package.json b/package.json
index 55675a03..f02e43e6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "route-engine-js",
-  "version": "0.7.5",
+  "version": "0.7.6",
   "description": "A lightweight Visual Novel engine built in JavaScript for creating interactive narrative games with branching storylines",
   "repository": {
     "type": "git",
diff --git a/spec/system/renderState/addCharacters.spec.yaml b/spec/system/renderState/addCharacters.spec.yaml
index 2b91de22..6d56dc78 100644
--- a/spec/system/renderState/addCharacters.spec.yaml
+++ b/spec/system/renderState/addCharacters.spec.yaml
@@ -51,7 +51,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body-face"
+          id: "character-container-char1"
           x: 100
           y: 200
           anchorX: 0.5
@@ -61,14 +61,14 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-face-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
               x: 0
               y: 0
             - type: "sprite"
-              id: "character-container-char1-0-body-face-face"
+              id: "character-container-char1-face"
               src: "face.png"
               width: 200
               height: 200
@@ -128,7 +128,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 50
           y: 100
           anchorX: 0
@@ -138,7 +138,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -147,7 +147,7 @@ out:
   animations:
     - id: "character-animation-in"
       type: "transition"
-      targetId: "character-container-char1-0-body"
+      targetId: "character-container-char1"
       next:
         tween:
           alpha:
@@ -199,7 +199,7 @@ out:
   animations:
     - id: "character-animation-out"
       type: "transition"
-      targetId: "character-container-char1-0-body"
+      targetId: "character-container-char1"
       prev:
         tween:
           alpha:
@@ -260,7 +260,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 0
           y: 0
           anchorX: 0.5
@@ -270,7 +270,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -279,7 +279,7 @@ out:
   animations:
     - id: "character-animation-in"
       type: "transition"
-      targetId: "character-container-char1-0-body"
+      targetId: "character-container-char1"
       next:
         tween:
           alpha:
@@ -351,7 +351,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 0
           y: 0
           anchorX: 0.5
@@ -361,7 +361,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -370,7 +370,7 @@ out:
   animations:
     - id: "character-animation-update"
       type: "update"
-      targetId: "character-container-char1-0-body"
+      targetId: "character-container-char1"
       tween:
         scaleX:
           keyframes:
@@ -383,6 +383,120 @@ out:
               value: 2.2
               easing: easeOutQuad
 ---
+case: keep stable character target when swapping a sprite part on update
+in:
+  - elements:
+      - id: "story"
+        type: "container"
+        x: 0
+        y: 0
+        children: []
+    animations: []
+  - presentationState:
+      character:
+        items:
+          - id: "char1"
+            transformId: "transform1"
+            sprites:
+              - id: "body"
+                resourceId: "body"
+              - id: "face"
+                resourceId: "face-smile"
+            animations:
+              resourceId: "scaleUp"
+    previousPresentationState:
+      character:
+        items:
+          - id: "char1"
+            sprites:
+              - id: "body"
+                resourceId: "body"
+              - id: "face"
+                resourceId: "face-neutral"
+    resources:
+      transforms:
+        transform1:
+          x: 240
+          y: 320
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+      images:
+        body:
+          fileId: "body.png"
+          width: 200
+          height: 300
+        face-neutral:
+          fileId: "face-neutral.png"
+          width: 200
+          height: 300
+        face-smile:
+          fileId: "face-smile.png"
+          width: 200
+          height: 300
+      animations:
+        scaleUp:
+          type: update
+          tween:
+            scaleX:
+              keyframes:
+                - duration: 600
+                  value: 1.1
+                  easing: easeOutQuad
+            scaleY:
+              keyframes:
+                - duration: 600
+                  value: 1.1
+                  easing: easeOutQuad
+out:
+  elements:
+    - id: "story"
+      type: "container"
+      x: 0
+      y: 0
+      children:
+        - type: "container"
+          id: "character-container-char1"
+          x: 240
+          y: 320
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+          children:
+            - type: "sprite"
+              id: "character-container-char1-body"
+              src: "body.png"
+              width: 200
+              height: 300
+              x: 0
+              y: 0
+            - type: "sprite"
+              id: "character-container-char1-face"
+              src: "face-smile.png"
+              width: 200
+              height: 300
+              x: 0
+              y: 0
+  animations:
+    - id: "character-animation-update"
+      type: "update"
+      targetId: "character-container-char1"
+      tween:
+        scaleX:
+          keyframes:
+            - duration: 600
+              value: 1.1
+              easing: easeOutQuad
+        scaleY:
+          keyframes:
+            - duration: 600
+              value: 1.1
+              easing: easeOutQuad
+---
 case: multiple characters with different sprites
 in:
   - elements:
@@ -446,7 +560,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body-face"
+          id: "character-container-char1"
           x: 100
           y: 100
           anchorX: 0.5
@@ -456,21 +570,21 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-face-body"
+              id: "character-container-char1-body"
               src: "char1_body.png"
               width: 200
               height: 200
               x: 0
               y: 0
             - type: "sprite"
-              id: "character-container-char1-0-body-face-face"
+              id: "character-container-char1-face"
               src: "char1_face.png"
               width: 200
               height: 200
               x: 0
               y: 0
         - type: "container"
-          id: "character-container-char2-1-body2"
+          id: "character-container-char2"
           x: 200
           y: 100
           anchorX: 0.5
@@ -480,7 +594,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char2-1-body2-body2"
+              id: "character-container-char2-body2"
               src: "char2_body.png"
               width: 200
               height: 200
@@ -488,6 +602,94 @@ out:
               y: 0
   animations: []
 ---
+case: keep legacy distinct ids when duplicate character ids are authored
+in:
+  - elements:
+      - id: "story"
+        type: "container"
+        x: 0
+        y: 0
+        children: []
+    animations: []
+  - presentationState:
+      character:
+        items:
+          - id: "char1"
+            transformId: "transform1"
+            sprites:
+              - id: "body"
+                resourceId: "body"
+          - id: "char1"
+            transformId: "transform2"
+            sprites:
+              - id: "body"
+                resourceId: "body"
+    resources:
+      transforms:
+        transform1:
+          x: 100
+          y: 100
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+        transform2:
+          x: 300
+          y: 100
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+      images:
+        body:
+          fileId: "body.png"
+          width: 200
+          height: 300
+out:
+  elements:
+    - id: "story"
+      type: "container"
+      x: 0
+      y: 0
+      children:
+        - type: "container"
+          id: "character-container-char1-0-body"
+          x: 100
+          y: 100
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+          children:
+            - type: "sprite"
+              id: "character-container-char1-0-body-body"
+              src: "body.png"
+              width: 200
+              height: 300
+              x: 0
+              y: 0
+        - type: "container"
+          id: "character-container-char1-1-body"
+          x: 300
+          y: 100
+          anchorX: 0.5
+          anchorY: 1
+          rotation: 0
+          scaleX: 1
+          scaleY: 1
+          children:
+            - type: "sprite"
+              id: "character-container-char1-1-body-body"
+              src: "body.png"
+              width: 200
+              height: 300
+              x: 0
+              y: 0
+  animations: []
+---
 case: no presentationState.character - return unchanged state
 in:
   - elements:
@@ -715,7 +917,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 500
           y: 200
           anchorX: 0.5
@@ -725,7 +927,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -774,7 +976,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 100
           y: 600
           anchorX: 0.5
@@ -784,7 +986,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -834,7 +1036,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 300
           y: 400
           anchorX: 0.5
@@ -844,7 +1046,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
@@ -893,7 +1095,7 @@ out:
       y: 0
       children:
         - type: "container"
-          id: "character-container-char1-0-body"
+          id: "character-container-char1"
           x: 0
           y: 200
           anchorX: 0.5
@@ -903,7 +1105,7 @@ out:
           scaleY: 1
           children:
             - type: "sprite"
-              id: "character-container-char1-0-body-body"
+              id: "character-container-char1-body"
               src: "body.png"
               width: 200
               height: 200
diff --git a/src/stores/constructRenderState.js b/src/stores/constructRenderState.js
index edd43ba2..2d59bc01 100644
--- a/src/stores/constructRenderState.js
+++ b/src/stores/constructRenderState.js
@@ -341,7 +341,33 @@ const ensureDialogueContentItems = (content, path) => {
   return content;
 };
 
-const getCharacterContainerId = (item, index = 0) => {
+const getDuplicateItemIds = (items = []) => {
+  const counts = new Map();
+
+  for (const item of items) {
+    if (!item?.id) {
+      continue;
+    }
+
+    counts.set(item.id, (counts.get(item.id) ?? 0) + 1);
+  }
+
+  return new Set(
+    Array.from(counts.entries())
+      .filter(([, count]) => count > 1)
+      .map(([id]) => id),
+  );
+};
+
+const getCharacterContainerId = (
+  item,
+  index = 0,
+  duplicateCharacterIds = new Set(),
+) => {
+  if (!duplicateCharacterIds.has(item?.id)) {
+    return `character-container-${item.id}`;
+  }
+
   const spritePartIds =
     item?.sprites?.map(({ resourceId }) => resourceId) || [];
 
@@ -1419,6 +1445,8 @@ export const addCharacters = (
 
     const items = presentationState.character.items || [];
     const previousItems = previousPresentationState?.character?.items || [];
+    const duplicateCharacterIds = getDuplicateItemIds(items);
+    const previousDuplicateCharacterIds = getDuplicateItemIds(previousItems);
 
     for (let i = 0; i < items.length; i++) {
       const item = items[i];
@@ -1434,7 +1462,11 @@ export const addCharacters = (
       const currentHasSprites = sprites && sprites.length > 0;
       const previousContainerId =
         previousItemIndex >= 0
-          ? getCharacterContainerId(previousItem, previousItemIndex)
+          ? getCharacterContainerId(
+              previousItem,
+              previousItemIndex,
+              previousDuplicateCharacterIds,
+            )
           : undefined;
 
       if (
@@ -1471,7 +1503,11 @@ export const addCharacters = (
         continue;
       }
 
-      const containerId = getCharacterContainerId(item, i);
+      const containerId = getCharacterContainerId(
+        item,
+        i,
+        duplicateCharacterIds,
+      );
       const transform = resources.transforms[transformId];
       if (!transform) {
         console.warn("Transform not found:", transformId);
diff --git a/vt/reference/background/transition-tween-out-02.webp b/vt/reference/background/transition-tween-out-02.webp
index 5207f05d..168d87b0 100644
--- a/vt/reference/background/transition-tween-out-02.webp
+++ b/vt/reference/background/transition-tween-out-02.webp
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:492076e4ced59a7faf8324016f6d2fdbb0228e8ab083ca9daddc01886df56d18
-size 10860
+oid sha256:0ac3868abc283729fbdba4a6d760dfb680459f97a2d3ef15c173b13ba329775e
+size 6946
diff --git a/vt/reference/background/update-enter-fallback-02.webp b/vt/reference/background/update-enter-fallback-02.webp
index 5207f05d..5c3a410c 100644
--- a/vt/reference/background/update-enter-fallback-02.webp
+++ b/vt/reference/background/update-enter-fallback-02.webp
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:492076e4ced59a7faf8324016f6d2fdbb0228e8ab083ca9daddc01886df56d18
-size 10860
+oid sha256:057c496fd951296b1b477e9172f12a6a7f4d32b32ba088a33b2648358a121c6e
+size 3948
diff --git a/vt/reference/character/sprite-parts-update-01.webp b/vt/reference/character/sprite-parts-update-01.webp
new file mode 100644
index 00000000..d3f3d395
--- /dev/null
+++ b/vt/reference/character/sprite-parts-update-01.webp
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b7d05e449c914e657f1d4f8082f961a9a456c152d541bd9a4d304442b9a277dc
+size 2576
diff --git a/vt/reference/character/sprite-parts-update-02.webp b/vt/reference/character/sprite-parts-update-02.webp
new file mode 100644
index 00000000..d3f3d395
--- /dev/null
+++ b/vt/reference/character/sprite-parts-update-02.webp
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b7d05e449c914e657f1d4f8082f961a9a456c152d541bd9a4d304442b9a277dc
+size 2576
diff --git a/vt/reference/character/sprite-parts-update-03.webp b/vt/reference/character/sprite-parts-update-03.webp
new file mode 100644
index 00000000..e15b735d
--- /dev/null
+++ b/vt/reference/character/sprite-parts-update-03.webp
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ee2544f8f11bff90f3871ab467dd7489bd2b2304947d557b10ea8a12056fe8e0
+size 2678
diff --git a/vt/reference/character/sprite-parts-update-04.webp b/vt/reference/character/sprite-parts-update-04.webp
new file mode 100644
index 00000000..7208a784
--- /dev/null
+++ b/vt/reference/character/sprite-parts-update-04.webp
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b2f0e1499b874f6a0d99fca35f03663095d5e83eaf1a07548e12efb3deddd384
+size 2758
diff --git a/vt/specs/character/sprite-parts-update.yaml b/vt/specs/character/sprite-parts-update.yaml
new file mode 100644
index 00000000..0b502b6f
--- /dev/null
+++ b/vt/specs/character/sprite-parts-update.yaml
@@ -0,0 +1,116 @@
+---
+title: Character Sprite Parts Update
+description: |
+  Same-character sprite-part swaps should preserve the composed character target
+  so update animations still run on the container instead of degrading into a
+  replace path.
+specs:
+  - the initial screenshot should show one composed grayscale character with a neutral face
+  - the post-advance screenshot should swap only the face part while keeping the same character target
+  - the halfway screenshot should show the smiling face and an in-progress scale update
+  - the final screenshot should settle on the smiling face at the final scale
+steps:
+  - action: customEvent
+    name: vt:nextLine
+  - action: screenshot
+  - action: customEvent
+    name: snapShotKeyFrame
+    detail:
+      deltaMS: 300
+  - action: screenshot
+  - action: customEvent
+    name: snapShotKeyFrame
+    detail:
+      deltaMS: 300
+  - action: screenshot
+---
+screen:
+  width: 1920
+  height: 1080
+  backgroundColor: "#000000"
+resources:
+  controls:
+    base1:
+      elements:
+        - id: click-area
+          type: rect
+          width: 1920
+          height: 1080
+          alpha: 0.001
+          click:
+            payload:
+              actions:
+                nextLine: {}
+          colorId: overlayColor
+  images:
+    parts-body:
+      fileId: character_parts_body
+      width: 620
+      height: 960
+    parts-face-neutral:
+      fileId: character_parts_face_neutral
+      width: 620
+      height: 960
+    parts-face-smile:
+      fileId: character_parts_face_smile
+      width: 620
+      height: 960
+  transforms:
+    center-stage:
+      x: 960
+      y: 1080
+      anchorX: 0.5
+      anchorY: 1
+  animations:
+    part-swap-scale:
+      name: Character Part Swap Scale
+      type: update
+      tween:
+        scaleX:
+          keyframes:
+            - duration: 600
+              value: 1.2
+              easing: linear
+        scaleY:
+          keyframes:
+            - duration: 600
+              value: 1.2
+              easing: linear
+  colors:
+    overlayColor:
+      hex: "#000000"
+story:
+  initialSceneId: characterPartsScene
+  scenes:
+    characterPartsScene:
+      name: Character Parts Scene
+      initialSectionId: main
+      sections:
+        main:
+          lines:
+            - id: line1
+              actions:
+                control:
+                  resourceId: base1
+                character:
+                  items:
+                    - id: grayscale-hero
+                      transformId: center-stage
+                      sprites:
+                        - id: body
+                          resourceId: parts-body
+                        - id: face
+                          resourceId: parts-face-neutral
+            - id: line2
+              actions:
+                character:
+                  items:
+                    - id: grayscale-hero
+                      transformId: center-stage
+                      sprites:
+                        - id: body
+                          resourceId: parts-body
+                        - id: face
+                          resourceId: parts-face-smile
+                      animations:
+                        resourceId: part-swap-scale
diff --git a/vt/static/main.js b/vt/static/main.js
index aaeeab74..85b2ee03 100644
--- a/vt/static/main.js
+++ b/vt/static/main.js
@@ -97,6 +97,18 @@ const init = async () => {
       url: "/public/characters/sprite-2-2.png",
       type: "image/png",
     },
+    character_parts_body: {
+      url: "/public/characters/parts-body-base.png",
+      type: "image/png",
+    },
+    character_parts_face_neutral: {
+      url: "/public/characters/parts-face-neutral.png",
+      type: "image/png",
+    },
+    character_parts_face_smile: {
+      url: "/public/characters/parts-face-smile.png",
+      type: "image/png",
+    },
     "94lkj289": {
       url: "/public/logo1.png",
       type: "image/png",
diff --git a/vt/static/public/characters/parts-body-base.png b/vt/static/public/characters/parts-body-base.png
new file mode 100644
index 00000000..cda29249
--- /dev/null
+++ b/vt/static/public/characters/parts-body-base.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4770e6017445bae603c784d31fd1688812cf9899d07b594827bdb5427f71e3ad
+size 20901
diff --git a/vt/static/public/characters/parts-face-neutral.png b/vt/static/public/characters/parts-face-neutral.png
new file mode 100644
index 00000000..034e9048
--- /dev/null
+++ b/vt/static/public/characters/parts-face-neutral.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:39d6508ea4271dcbb9f3adc36b66bf748cd4898007731006f3ef887ca0e6362f
+size 6263
diff --git a/vt/static/public/characters/parts-face-smile.png b/vt/static/public/characters/parts-face-smile.png
new file mode 100644
index 00000000..e64ef9f8
--- /dev/null
+++ b/vt/static/public/characters/parts-face-smile.png
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