diff --git a/server/fixtures/rock-projectile.entity.js b/server/fixtures/rock-projectile.entity.js
index 953efe0..a2bc39a 100644
--- a/server/fixtures/rock-projectile.entity.js
+++ b/server/fixtures/rock-projectile.entity.js
@@ -28,15 +28,35 @@ export function rockProjectileJSON() {
     ['entity', 'direction'],
     buildTraversal(['wielder', 'direction']),
   );
-  const move = buildInvoke(['entity', 'moveFor'], [
-    buildInvoke(
-      ['Vector', 'fromDirection'],
-      [
-        buildTraversal(['entity', 'direction']),
-      ],
-    ),
-    0.5,
-  ]);
+  const move = buildInvoke(
+    ['entity', 'moveFor'],
+    [
+      buildInvoke(
+        ['Vector', 'fromDirection'],
+        [
+          buildTraversal(['entity', 'direction']),
+        ],
+      ),
+      0.5,
+    ],
+  );
+  const setIsNotDamaging = buildTraversal(
+    ['entity', 'isDamaging'],
+    false,
+  );
+  const reflect = buildInvoke(
+    ['entity', 'moveFor'],
+    [
+      buildInvoke(
+        ['Vector', 'sub'],
+        [
+          buildTraversal(['entity', 'position']),
+          buildTraversal(['obstacle', 'position']),
+        ],
+      ),
+      0.05,
+    ],
+  );
   // Destroy.
   const destroy = buildInvoke(
     ['entity', 'destroy'],
@@ -62,11 +82,15 @@ export function rockProjectileJSON() {
                   ],
                 },
               },
-              dry: {
+              reflect: {
                 type: 'routine',
                 routine: {
                   type: 'actions',
-                  traversals: [],
+                  traversals: [
+                    setIsNotDamaging,
+                    reflect,
+                    destroy,
+                  ],
                 },
               },
             },
@@ -78,12 +102,22 @@ export function rockProjectileJSON() {
       },
       collider: {
         params: {
-          // collisionStartActions: {
-          //   type: 'actions',
-          //   traversals: [
-          //     buildInvoke(['entity', 'destroy']),
-          //   ],
-          // },
+          collisionStartActions: {
+            type: 'actions',
+            traversals: [
+              buildInvoke(
+                ['entity', 'context', 'set'],
+                [
+                  'obstacle',
+                  buildTraversal(['other']),
+                ],
+              ),
+              buildTraversal(
+                ['entity', 'currentRoutine'],
+                'reflect',
+              ),
+            ],
+          },
           isSensor: true,
         },
       },
@@ -93,7 +127,7 @@ export function rockProjectileJSON() {
             {
               affinity: AFFINITY_NONE,
               knockback: 500,
-              lock: 0.25,
+              lock: 1,
               power: 50,
               variance: 0.1,
             },