diff --git a/include/Observer.hpp b/include/Observer.hpp
new file mode 100644
index 0000000..220bf42
--- /dev/null
+++ b/include/Observer.hpp
@@ -0,0 +1,15 @@
+#ifndef OBSERVER_HPP
+#define OBSERVER_HPP
+
+class Subject;
+
+class Observer
+{
+public:
+
+  virtual ~Observer();
+  virtual void update( Subject* ) = 0;
+};
+
+
+#endif // OBSERVER_HPP
diff --git a/include/Subject.cpp b/include/Subject.cpp
new file mode 100644
index 0000000..59057e7
--- /dev/null
+++ b/include/Subject.cpp
@@ -0,0 +1,23 @@
+#ifndef SUBJECT_HPP
+#define SUBJECT_HPP
+
+#include <list>
+
+class Observer;
+
+class Subject
+{
+public:
+
+  virtual ~Subject();
+
+  virtual void attach( Observer* );
+  virtual void detach( Observer* );
+  virtual void notify();
+
+private:
+  std::list< Observer* > m_observers;
+
+};
+
+#endif // SUBJECT_HPP
\ No newline at end of file