diff --git a/src/coord.h b/src/coord.h
index 63b0b2f..9d4a8a7 100644
--- a/src/coord.h
+++ b/src/coord.h
@@ -75,7 +75,7 @@ struct Coord
 };
 
 struct CoordHash{
-    size_t operator()(const Coord& val) const{
+    std::size_t operator()(const Coord& val) const{
         return val.x+10000*val.y;
     }
 };
diff --git a/src/dude.cpp b/src/dude.cpp
index 0f2c853..94de427 100644
--- a/src/dude.cpp
+++ b/src/dude.cpp
@@ -2,7 +2,7 @@
 #include "map.h"
 #include <cstring>
 
-Dude::Dude(const Coord &_pos, Map *_map, int &_team) :
+Dude::Dude(const Coord &_pos, Map *_map, const int &_team) :
     m_pos(_pos),
     p_map(_map),
     m_team(_team),
@@ -49,6 +49,7 @@ void Dude::update(BehaviorFunction func)
 {
     func(&m_action, m_memory, (Info*)this);
     m_receivedComData = false;
+    memcpy(m_com_data.data, 0, COM_SIZE);
 }
 
 PixelType Dude::getNear(Dir d) const
diff --git a/src/dude.h b/src/dude.h
index 48e8dc4..8eaa6e7 100644
--- a/src/dude.h
+++ b/src/dude.h
@@ -20,22 +20,31 @@ private:
     int m_underResCount;
     
 public:
-    Dude(const Coord &_pos, Map *_map, int &_team);
+    Dude(const Coord &_pos, Map *_map, const int &_team);
+    //general use functions
+    void update(BehaviorFunction func);
     const Action& getAction() { return m_action; }
     int getTeam(){ return m_team; }
-    void setSuccess(bool success) { m_success = success; }
-    void setInventory(PixelType item) { m_inventory = item; }
+
+    //life-related function
+    bool isAlive() { return !m_dead; }
     void perish() { m_dead = true; }
+
+    //movement-related function
     const Coord& getPos() { return m_pos; }
     void move(Dir d);
-    void receiveComData(Dir dir, const char *data);
-    void update(BehaviorFunction func);
     
+    //function inherited from Info
     virtual bool getSuccess() const { return m_success; }
     virtual PixelType getInventory() const { return m_inventory; }
     virtual const Com* getCom() const { return m_receivedComData ? &m_com_data : nullptr; }
     virtual PixelType getNear(Dir d) const;
     virtual int getInfo(Dir d) const;
+
+    // setter for the variable returned by functions of Info
+    void setSuccess(bool success) { m_success = success; }
+    void setInventory(PixelType item) { m_inventory = item; }
+    void receiveComData(Dir dir, const char *data);
 };
 
 #endif // DUDE_H
diff --git a/src/map.h b/src/map.h
index edc7a60..40aabae 100644
--- a/src/map.h
+++ b/src/map.h
@@ -11,7 +11,7 @@ struct Pixel
         int nbRes; // RESOURCES
         char *knowledge; // LIBRARY
         int teamId; // SPAWN
-        Dude* dudePtr; // DUDE
+        Dude *dudePtr; // DUDE
     };
     
     PixelType type;
diff --git a/src/simulation.cpp b/src/simulation.cpp
index 1a15961..147194d 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -32,13 +32,18 @@ Simulation::~Simulation()
 void Simulation::update()
 {
     std::random_shuffle(m_dudes.begin(), m_dudes.end());
-    for (int i=0; i<m_dudes.size(); ++i){
+    for (unsigned int i=0; i<m_dudes.size(); ++i){
         Dude *dude = m_dudes[i];
-        m_teams[dude->getTeam()].update(dude); //get action for this dude from behavior function in team
-        handleAction(dude);
+        if (dude->isAlive()){
+            m_teams[dude->getTeam()].update(dude); //get action for this dude from behavior function in team
+            handleAction(dude);
+        }
     }
+
+    resolveBattles();
+
     // for each team, spawn dude if condition met
-    for(int i=0; i<m_teams.size(); ++i){
+    for(unsigned int i=0; i<m_teams.size(); ++i){
         Team &t = m_teams[i];
         if(t.updateSpawn())
         {
@@ -77,8 +82,8 @@ void Simulation::handleAction(Dude *dude)
         if(PixelProperty::isDestructible(target.type))
         {
             dude->setSuccess(true);
-            if (target.type == DUDE) // TODO:  add fight between dude and targetDude
-                NULL;
+            if (target.type == DUDE) //DONE
+                m_battles.insert(Battle(dude,target.data.dudePtr));
             else // DONE
             {
                 if(target.type == SPAWN)
@@ -190,17 +195,23 @@ void Simulation::handleAction(Dude *dude)
         {
             Dude *targetDude = target.data.dudePtr;
             // TODO check conflicts between writers
-            targetDude->receiveComData(Dir((action.dir+2)%4), targetDude->getAction().com_data.data);
-            dude->setSuccess(true);
+            if(targetDude->getCom() == nullptr){
+                targetDude->receiveComData(Dir((action.dir+2)%4), targetDude->getAction().com_data.data);
+                dude->setSuccess(true);
+            }else
+                dude->setSuccess(false);
             break;
         }
         case LIBRARY:
         {
             int offset = (action.com_data.flag & 3)*COM_SIZE;
             if(action.com_data.flag & Com::READ)
-                dude->receiveComData(action.dir, target.data.knowledge + offset);
-            else
-            {
+                if(dude->getCom() == nullptr){
+                    dude->receiveComData(action.dir, target.data.knowledge + offset);
+                    dude->setSuccess(true);
+                }else
+                    dude->setSuccess(false);
+            else{
                 memcpy(target.data.knowledge + offset, action.com_data.data, COM_SIZE);
                 dude->setSuccess(true);
             }
@@ -211,3 +222,33 @@ void Simulation::handleAction(Dude *dude)
         }
     }
 }
+
+// TODO: verify if battle resolution work
+void Simulation::resolveBattles(){
+    for (Battle battle : m_battles){
+        Dude *attacker = battle.first, *defender = battle.second;
+        if (defender->isAlive() && defender->getAction().type == Action::ATTACK){
+            if (attacker->getPos() == defender->getPos() + Coord(defender->getAction().dir)){
+                bool armedAttacker = attacker->getInventory() == PixelType::SWORD, armedDefender = defender->getInventory() == PixelType::SWORD;
+                if (armedAttacker == armedDefender){
+                    if ((rand()%100 + 1) > 50)
+                        attacker->perish();
+                    else
+                        defender->perish();
+                }else if(armedAttacker){
+                    if ((rand()%100 + 1) > 80)
+                        attacker->perish();
+                    else
+                        defender->perish();
+                }else if(armedDefender){
+                    if ((rand()%100 + 1) > 20)
+                        attacker->perish();
+                    else
+                        defender->perish();
+                }
+            }else
+                defender->perish();
+        }else
+            defender->perish();
+    }
+}
diff --git a/src/simulation.h b/src/simulation.h
index 75650d8..9f11efe 100644
--- a/src/simulation.h
+++ b/src/simulation.h
@@ -2,6 +2,8 @@
 #define SIMULATION_H
 
 #include <vector>
+#include <set>
+#include <tuple>
 #include "behavior.h"
 #include "team.h"
 
@@ -10,9 +12,21 @@ class MapScene;
 class Simulation
 {
 private:
+    typedef std::pair<Dude*,Dude*> Battle;
+    struct battleComparator{
+        bool operator() (Battle a, Battle b){
+            return ((a == b) || (a.first == b.second && b.first == a.second));
+        }
+    };
+
     MapScene *p_map;
     std::vector<Dude*> m_dudes;
     std::vector<Team> m_teams;
+    std::set<Battle,battleComparator> m_battles;
+
+    void handleAction(Dude* dude);
+    void resolveBattles();
+
 public:
     Simulation(MapScene *_map, std::vector<BehaviorFunction> &_behaviors);
     ~Simulation();
@@ -23,7 +37,6 @@ public:
      * @brief update runs one step of simulation
      */
     void update();
-    void handleAction(Dude* dude);
 };
 
 #endif // SIMULATION_H