diff --git a/src/model/Dog.cpp b/src/model/Dog.cpp
new file mode 100644
index 0000000..ee8f636
--- /dev/null
+++ b/src/model/Dog.cpp
@@ -0,0 +1 @@
+#include "Dog.h"
diff --git a/src/model/Dog.h b/src/model/Dog.h
new file mode 100644
index 0000000..a23e1e2
--- /dev/null
+++ b/src/model/Dog.h
@@ -0,0 +1,5 @@
+namespace model
+{
+class Dog
+{};
+}
diff --git a/src/model/Game.h b/src/model/Game.h
index 5d48932..91b0688 100644
--- a/src/model/Game.h
+++ b/src/model/Game.h
@@ -3,11 +3,13 @@
 #include <vector>
 
 #include "Map.h"
+#include "GameSession.h"
 
 namespace model
 {
 class Game
 {
   std::vector<Map> maps_;
+  std::vector<GameSession> sessions_;
 };
 }
diff --git a/src/model/GameSession.cpp b/src/model/GameSession.cpp
new file mode 100644
index 0000000..4147c91
--- /dev/null
+++ b/src/model/GameSession.cpp
@@ -0,0 +1 @@
+#include "GameSession.h"
diff --git a/src/model/GameSession.h b/src/model/GameSession.h
new file mode 100644
index 0000000..9891336
--- /dev/null
+++ b/src/model/GameSession.h
@@ -0,0 +1,14 @@
+#include <vector>
+#include <memory>
+
+#include "Dog.h"
+#include "Map.h"
+
+namespace model
+{
+class GameSession
+{
+  std::vector<Dog> dogs_;
+  std::shared_ptr<Map> map_;
+};
+}