diff --git a/arduino_pong.ino b/arduino_pong.ino
index 09d317a..c13d304 100644
--- a/arduino_pong.ino
+++ b/arduino_pong.ino
@@ -21,7 +21,7 @@ byte frame[MATRIX_HEIGHT][MATRIX_WIDTH] = {
 
 ArduinoLEDMatrix matrix;
 
-int need_refresh= true;
+bool need_refresh= true;
 uint8_t hits= 0;
 long exec_t2= millis();
 
@@ -35,8 +35,8 @@ enum game_statuses : uint8_t {
 game_statuses game_status= TIMER;
 
 Ball ball(4, 6);
-Paddle p1(1);
-Paddle p2(4);
+HumanPaddle p1(1, P1_BTN_UP, P1_BTN_BOTTOM);
+HumanPaddle p2(4, P2_BTN_UP, P2_BTN_BOTTOM);
 Engine engine(p1, p2, ball, INITIAL_BALL_DELAY);
 Renderer renderer(p1, p2, ball, frame, matrix);
 
@@ -69,7 +69,8 @@ void loop() {
       break;
 
     case RUN:
-      need_refresh= check_paddle_movements(p1, p2);
+      // need_refresh= check_paddle_movements(p1, p2);
+      need_refresh= engine.control_players();
 
       if (exec_t1 - exec_t2 > engine.ball_movement_delay()) {
         engine.run();
diff --git a/src/engine.cpp b/src/engine.cpp
index ccb6890..ad2b557 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -60,6 +60,13 @@ void Engine::run() {
   }
 }
 
+bool Engine::control_players() {
+  bool need_refresh= false;
+  need_refresh |= _p1.check_pad_movement();
+  need_refresh |= _p2.check_pad_movement();
+  return need_refresh;
+}
+
 uint8_t Engine::ball_movement_delay() {
   return _ball_mv_delay;
 }
diff --git a/src/engine.h b/src/engine.h
index 61051dd..5f453c8 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -26,6 +26,7 @@ class Engine {
         : _p1(p_one), _p2(p_two), _ball(ball), _ball_mv_delay(ball_mv_delay) {}
 
     void run();
+    bool control_players();
     uint8_t ball_movement_delay();
     EngineEvents get_event();
     void restart_ball();
diff --git a/src/paddle.cpp b/src/paddle.cpp
index 9e1ed03..ffccb46 100644
--- a/src/paddle.cpp
+++ b/src/paddle.cpp
@@ -11,6 +11,9 @@ void Paddle::move_pad_down() {
   }
 }
 
+void run_paddle() {
+}
+
 uint8_t Paddle::get_position() {
   return _position;
 }
@@ -31,24 +34,23 @@ void Paddle::reset() {
   _score= 0;
 }
 
-bool check_paddle_movements(Paddle &p1, Paddle &p2) {
-  bool need_refresh= false;
-  if (digitalRead(P1_BTN_UP) == LOW) {
-    p1.move_pad_up();
-    need_refresh= true;
-  }
-  else if (digitalRead(P1_BTN_BOTTOM) == LOW) {
-    p1.move_pad_down();
-    need_refresh= true;
-  }
+bool Paddle::check_pad_movement() {
+  // redefine me
+  return false;
+}
 
-  if (digitalRead(P2_BTN_UP) == LOW) {
-    p2.move_pad_up();
+bool HumanPaddle::check_pad_movement() {
+  bool need_refresh= false;
+  if (digitalRead(_pin_btn_top) == LOW) {
+    this -> move_pad_up();
     need_refresh= true;
   }
-  else if (digitalRead(P2_BTN_BOTTOM) == LOW) {
-    p2.move_pad_down();
+  else if (digitalRead(_pin_btn_bottom) == LOW) {
+    this -> move_pad_down();
     need_refresh= true;
   }
   return need_refresh;
 }
+
+bool BotPaddle::check_pad_movement() {
+}
diff --git a/src/paddle.h b/src/paddle.h
index 55cca24..79f5588 100644
--- a/src/paddle.h
+++ b/src/paddle.h
@@ -6,15 +6,15 @@
 
 class Paddle {
 
-  private:
+  protected:
     // define player coordinates
     uint8_t _position;
     uint8_t _height= PADDLE_LENGTH;
     uint8_t _score= 0;
-    bool _human= true;
+    bool _human;
 
   public:
-    Paddle (uint8_t _position) : _position(_position) {}
+    Paddle (uint8_t position, bool human) : _position(position), _human(human) {}
     void move_pad_up();
     void move_pad_down();
     uint8_t get_position();
@@ -22,8 +22,30 @@ class Paddle {
     void increase_score();
     uint8_t get_score();
     void reset();
+    virtual bool check_pad_movement();
 };
 
-bool check_paddle_movements(Paddle &p1, Paddle &p2);
+class HumanPaddle : public Paddle {
+  private:
+    uint8_t _pin_btn_top;
+    uint8_t _pin_btn_bottom;
+  public:
+    HumanPaddle(uint8_t position, uint8_t pin_btn_top, uint8_t pin_btn_bottom) 
+              : Paddle(position, true), _pin_btn_top(pin_btn_top), _pin_btn_bottom(pin_btn_bottom) {}
+    bool check_pad_movement();
+};
+
+class BotPaddle : public Paddle {
+  private:
+    uint8_t _level; // this is the difficulty level
+
+  public:
+    BotPaddle(uint8_t position, uint8_t level) 
+              : Paddle(position, false), _level(level) {
+                if (_level < 1) _level= 1;
+                if (_level > 3) _level= 3;
+              }
+    bool check_pad_movement();
+};
 
 #endif