diff --git a/doomsday/client/include/world/thinkers.h b/doomsday/client/include/world/thinkers.h
index fe413f1688..fb79beae21 100644
--- a/doomsday/client/include/world/thinkers.h
+++ b/doomsday/client/include/world/thinkers.h
@@ -95,6 +95,15 @@ class Thinkers
      */
     void setMobjId(thid_t id, bool inUse = true);
 
+    /**
+     * Returns the total number of thinkers (of any type) in the collection.
+     *
+     * @param numInStasis  If not @c NULL, the number of thinkers in stasis will
+     *                     be added to the current value (caller must ensure to
+     *                     initialize this).
+     */
+    int count(int *numInStasis = 0) const;
+
 private:
     DENG2_PRIVATE(d)
 };
diff --git a/doomsday/client/src/world/thinkers.cpp b/doomsday/client/src/world/thinkers.cpp
index b1abd9882c..17a409cf40 100644
--- a/doomsday/client/src/world/thinkers.cpp
+++ b/doomsday/client/src/world/thinkers.cpp
@@ -86,6 +86,26 @@ struct ThinkerList
         sentinel.prev = &th;
     }
 
+    int count(int *numInStasis) const
+    {
+        int num = 0;
+        thinker_t *th = sentinel.next;
+        while(th != &sentinel && th)
+        {
+#ifdef LIBDENG_FAKE_MEMORY_ZONE
+            DENG_ASSERT(th->next != 0);
+            DENG_ASSERT(th->prev != 0);
+#endif
+            num += 1;
+            if(numInStasis && th->inStasis)
+            {
+                (*numInStasis) += 1;
+            }
+            th = th->next;
+        }
+        return num;
+    }
+
     int iterate(int (*callback) (thinker_t *, void *), void *parameters = 0)
     {
         int result = false;
@@ -337,6 +357,20 @@ int Thinkers::iterate(thinkfunc_t func, byte flags,
     return result;
 }
 
+int Thinkers::count(int *numInStasis) const
+{
+    int total = 0;
+    if(isInited())
+    {
+        for(int i = 0; i < d->lists.count(); ++i)
+        {
+            ThinkerList *list = d->lists[i];
+            total += list->count(numInStasis);
+        }
+    }
+    return total;
+}
+
 void unlinkThinkerFromList(thinker_t *th)
 {
     th->next->prev = th->prev;