diff --git a/ksirk/Dialogs/jabbergameui.h b/ksirk/Dialogs/jabbergameui.h
--- a/ksirk/Dialogs/jabbergameui.h
+++ b/ksirk/Dialogs/jabbergameui.h
@@ -17,8 +17,8 @@
    02110-1301, USA
 */
 
-#ifndef JABBERGAMEWIDGET_H
-#define JABBERGAMEWIDGET_H
+#ifndef JABBERGAMEUI_H
+#define JABBERGAMEUI_H
 
 #include "ui_jabbergameui.h"
 #include "Jabber/jabberclient.h"
@@ -38,7 +38,7 @@
 {
   Q_OBJECT
 public:
-  KsirkJabberGameWidget(QWidget* parent);
+  explicit KsirkJabberGameWidget(QWidget* parent);
 
   ~KsirkJabberGameWidget() override {}
                          
diff --git a/ksirk/Dialogs/kplayersetupwidget.h b/ksirk/Dialogs/kplayersetupwidget.h
--- a/ksirk/Dialogs/kplayersetupwidget.h
+++ b/ksirk/Dialogs/kplayersetupwidget.h
@@ -22,8 +22,8 @@
 #define KDE_NO_COMPAT
 
 
-#ifndef KPLAYERSETUPDIALOG_H
-#define KPLAYERSETUPDIALOG_H
+#ifndef KPLAYERSETUPWIDGET_H
+#define KPLAYERSETUPWIDGET_H
 
 #include "ui_qplayersetupdialog.h"
 
@@ -52,7 +52,7 @@
 {
   Q_OBJECT
 public:
-  KPlayerSetupWidget(QWidget *parent=0);
+  explicit KPlayerSetupWidget(QWidget *parent=0);
   
   ~KPlayerSetupWidget() override;
 
@@ -106,4 +106,4 @@
 
 }
 
-#endif // KPLAYERSETUPDIALOG_H
+#endif // KPLAYERSETUPWIDGET_H
diff --git a/ksirk/Dialogs/newGameDialogImpl.h b/ksirk/Dialogs/newGameDialogImpl.h
--- a/ksirk/Dialogs/newGameDialogImpl.h
+++ b/ksirk/Dialogs/newGameDialogImpl.h
@@ -46,7 +46,7 @@
 {
   Q_OBJECT
 public:
-  NewGameWidget(NewGameSetup* newGameSetup, QWidget *parent=0);
+  explicit NewGameWidget(NewGameSetup* newGameSetup, QWidget *parent=0);
 
   ~NewGameWidget() override;
 
diff --git a/ksirk/Dialogs/newGameSummaryWidget.h b/ksirk/Dialogs/newGameSummaryWidget.h
--- a/ksirk/Dialogs/newGameSummaryWidget.h
+++ b/ksirk/Dialogs/newGameSummaryWidget.h
@@ -48,7 +48,7 @@
 {
   Q_OBJECT
 public:
-  NewGameSummaryWidget(QWidget *parent=0);
+  explicit NewGameSummaryWidget(QWidget *parent=0);
   
   ~NewGameSummaryWidget() override;
 
diff --git a/ksirk/Dialogs/restartOrExitDialogImpl.h b/ksirk/Dialogs/restartOrExitDialogImpl.h
--- a/ksirk/Dialogs/restartOrExitDialogImpl.h
+++ b/ksirk/Dialogs/restartOrExitDialogImpl.h
@@ -39,7 +39,7 @@
 {
   Q_OBJECT
 public:
-  RestartOrExitDialogImpl(
+  explicit RestartOrExitDialogImpl(
       const QString& label,
       QWidget *parent=0);
   ~RestartOrExitDialogImpl() override;
diff --git a/ksirk/Dialogs/tcpconnectwidget.h b/ksirk/Dialogs/tcpconnectwidget.h
--- a/ksirk/Dialogs/tcpconnectwidget.h
+++ b/ksirk/Dialogs/tcpconnectwidget.h
@@ -34,7 +34,7 @@
 {
   Q_OBJECT
 public:
-  TcpConnectWidget(QWidget *parent=0);
+  explicit TcpConnectWidget(QWidget *parent=0);
   
   ~TcpConnectWidget() override;
   
diff --git a/ksirk/GameLogic/KMessageParts.h b/ksirk/GameLogic/KMessageParts.h
--- a/ksirk/GameLogic/KMessageParts.h
+++ b/ksirk/GameLogic/KMessageParts.h
@@ -59,13 +59,13 @@
       m_order_it++;
       return *this;
     }
-    bool operator==(const iterator& it)
+    bool operator==(const iterator& it) const
     {
       return ( (m_pixmaps_it == it.m_pixmaps_it)
               && (m_strings_it == it.m_strings_it)
               && (m_order_it == it.m_order_it) );
     }
-    bool operator!=(const iterator& it)
+    bool operator!=(const iterator& it) const
     {
       return !((*this)==it);
     }
diff --git a/ksirk/GameLogic/aiColsonPlayer.h b/ksirk/GameLogic/aiColsonPlayer.h
--- a/ksirk/GameLogic/aiColsonPlayer.h
+++ b/ksirk/GameLogic/aiColsonPlayer.h
@@ -53,7 +53,7 @@
   /** 
     * Constructor with simple initializations
     */
-  AIColsonPlayer(
+  explicit AIColsonPlayer(
           const QString & nomPlayer, unsigned int nbArmies,
           Nationality * myNation,  PlayersArray& players, ONU* world,
           GameAutomaton* game );
diff --git a/ksirk/GameLogic/aiColsonPlayer.cpp b/ksirk/GameLogic/aiColsonPlayer.cpp
--- a/ksirk/GameLogic/aiColsonPlayer.cpp
+++ b/ksirk/GameLogic/aiColsonPlayer.cpp
@@ -387,7 +387,7 @@
     int max = 0;
     int bonus = 0;
     for (continentsIt = m_world->getContinents().begin();
-          continentsIt!=continentsIt_end; continentsIt++)
+          continentsIt!=continentsIt_end; ++continentsIt)
     {
       const Continent* continent = *continentsIt;
       if (piCount[*it][continent] > 0)
@@ -961,7 +961,7 @@
   qCDebug(KSIRK_LOG) << "2";
   if (nb > 0)
   {
-    nb = rand() % nb;
+    nb = qrand() % nb;
     for ( int iCountry = 0;
           iCountry < m_world->getCountries().size();
           iCountry++)
@@ -1195,7 +1195,7 @@
   /* Try to conquier an entire continent */
   for (int   iCountry = 0;
        iCountry < m_world->getCountries().size();
-       iCountry++)
+       ++iCountry)
   {
     if ((RISK_GetOwnerOfCountry(iCountry) == this) &&
         (RISK_GetContinentOfCountry(iCountry) == continent) &&
diff --git a/ksirk/GameLogic/aiplayer.h b/ksirk/GameLogic/aiplayer.h
--- a/ksirk/GameLogic/aiplayer.h
+++ b/ksirk/GameLogic/aiplayer.h
@@ -49,7 +49,7 @@
   /** 
     * Constructor with simple initializations
     */
-  AIPlayer(
+  explicit AIPlayer(
           const QString & nomPlayer, unsigned int nbArmies,
           Nationality * myNation,  PlayersArray& players, ONU* world,
           GameAutomaton* game );
@@ -137,7 +137,7 @@
     void run () override;
     
   public:
-    MyThread(AIPlayer& p) : me(p) {}
+    explicit MyThread(AIPlayer& p) : me(p) {}
     void setStopMe ( bool value ) { stopMe = value; }
   private:
     /** indicates to the thread if the run method should return */
diff --git a/ksirk/GameLogic/aiplayerio.h b/ksirk/GameLogic/aiplayerio.h
--- a/ksirk/GameLogic/aiplayerio.h
+++ b/ksirk/GameLogic/aiplayerio.h
@@ -39,7 +39,7 @@
 {
 public:
   /** Constructor of the IO device for the given AI player. */
-  AIPlayerIO(AIPlayer* aiplayer);
+  explicit AIPlayerIO(AIPlayer* aiplayer);
 
   /** Default destructor. */
   ~AIPlayerIO() override;
diff --git a/ksirk/GameLogic/gameautomaton.cpp b/ksirk/GameLogic/gameautomaton.cpp
--- a/ksirk/GameLogic/gameautomaton.cpp
+++ b/ksirk/GameLogic/gameautomaton.cpp
@@ -441,7 +441,7 @@
       qCDebug(KSIRK_LOG) << "Nb Local:" << nbLocal;
       stream << nbLocal;
 
-      for (it = playerList()->begin(); it != it_end; it++)
+      for (it = playerList()->begin(); it != it_end; ++it)
       {
         if ( !((Player*)(*it))->isVirtual() )
         {
@@ -2068,7 +2068,7 @@
     if (sender == gameId()) break;
     stream >> statusBarId >> logStatus >> messagePartsNb;
     qCDebug(KSIRK_LOG) << "Got ChangeItem on " << statusBarId << " ; nb= " << messagePartsNb << endl;
-    for (messagePartsCounter = 0; messagePartsCounter < messagePartsNb; messagePartsCounter++)
+    for (messagePartsCounter = 0; messagePartsCounter < messagePartsNb; ++messagePartsCounter)
     {
       stream >> elemType;
       if (elemType == KMessageParts::Text)
diff --git a/ksirk/GameLogic/goal.h b/ksirk/GameLogic/goal.h
--- a/ksirk/GameLogic/goal.h
+++ b/ksirk/GameLogic/goal.h
@@ -61,7 +61,7 @@
     GoalAdvance = 2 /**< The advance step. */
   };
   
-  Goal(GameAutomaton* automaton);
+  explicit Goal(GameAutomaton* automaton);
   
   /** Copy constructor */
   Goal(const Goal& goal);
diff --git a/ksirk/GameLogic/goal.cpp b/ksirk/GameLogic/goal.cpp
--- a/ksirk/GameLogic/goal.cpp
+++ b/ksirk/GameLogic/goal.cpp
@@ -227,7 +227,7 @@
       case Goal::Continents:
         foreach (const QString& continent, m_continents)
         {
-          if (continent != QString())
+          if (!continent.isEmpty())
           {
             qCDebug(KSIRK_LOG) << "  arg = '" << continent << "'" << endl;
             res=res.subs(i18n(continent.toUtf8().data()));
@@ -463,7 +463,7 @@
   itc = continents().constBegin(); itc_end = continents().constEnd();
   for (; itc != itc_end; itc++)
   {
-    QString name = (*itc==QString())?"":(*itc);
+    QString name = ((*itc).isEmpty())?"":(*itc);
     xmlStream << "<continent name=\"" << name << "\"/>" << endl;
   }
   xmlStream << "</continents>" << endl;
diff --git a/ksirk/decoratedgameframe.h b/ksirk/decoratedgameframe.h
--- a/ksirk/decoratedgameframe.h
+++ b/ksirk/decoratedgameframe.h
@@ -42,7 +42,7 @@
   Q_OBJECT
   public:
     ArenaAction(QObject* parent = 0) : QAction(parent), m_arenaEnabled(false) {}
-    ArenaAction(const QString& text, QObject* parent = 0) : QAction(text, parent), m_arenaEnabled(false) {}
+    explicit ArenaAction(const QString& text, QObject* parent = 0) : QAction(text, parent), m_arenaEnabled(false) {}
     inline bool isArenaEnabled() {return m_arenaEnabled;}
     inline void setArenaEnabled(bool value) {m_arenaEnabled = value;}
   private:
diff --git a/ksirk/kgamewin.h b/ksirk/kgamewin.h
--- a/ksirk/kgamewin.h
+++ b/ksirk/kgamewin.h
@@ -128,7 +128,7 @@
   /**
     * Create the window and initializes its members
     */
-  KGameWindow(QWidget* parent=0);
+  explicit KGameWindow(QWidget* parent=0);
   
   /**
     * Deletes the background and the pool
diff --git a/ksirk/kgamewinslots.cpp b/ksirk/kgamewinslots.cpp
--- a/ksirk/kgamewinslots.cpp
+++ b/ksirk/kgamewinslots.cpp
@@ -951,7 +951,7 @@
   {
     qCDebug(KSIRK_LOG) << "my jid:" << m_groupchatRoom+'@'+m_groupchatHost+'/'+m_groupchatNick;
     XMPP::Jid jid ( message.from().domain() );
-    if (body.startsWith("I'm starting a game with skin")
+    if (body.startsWith(QLatin1String("I'm starting a game with skin"))
       && m_presents.contains(message.from().full ())
       && message.from().full() != m_groupchatRoom+'@'+m_groupchatHost+'/'+m_groupchatNick)
     {
@@ -963,7 +963,7 @@
       qCDebug(KSIRK_LOG) << "emiting newJabberGame" << nick << nbPlayers << skin;
       emit newJabberGame(nick, nbPlayers, skin);
     }
-    else if (body.startsWith("Who propose online KsirK games here?"))
+    else if (body.startsWith(QLatin1String("Who propose online KsirK games here?")))
     {
       qCDebug(KSIRK_LOG) << "online games question" << m_automaton->stateName();
       if (m_automaton->startingGame())
diff --git a/ksirk/mainMenu.h b/ksirk/mainMenu.h
--- a/ksirk/mainMenu.h
+++ b/ksirk/mainMenu.h
@@ -46,7 +46,7 @@
   Q_OBJECT
 
 public:
-  mainMenu(Ksirk::KGameWindow* game, QWidget* parent = 0);
+  explicit mainMenu(Ksirk::KGameWindow* game, QWidget* parent = 0);
 
   ~mainMenu() override {}
 
diff --git a/ksirkskineditor/ksirkSkinEditorConfigDialog.h b/ksirkskineditor/ksirkSkinEditorConfigDialog.h
--- a/ksirkskineditor/ksirkSkinEditorConfigDialog.h
+++ b/ksirkskineditor/ksirkSkinEditorConfigDialog.h
@@ -42,7 +42,7 @@
   /**
     * Constructor
     */
-  KsirkSkinEditorConfigurationDialog (
+  explicit KsirkSkinEditorConfigurationDialog (
                 QWidget *parent, const char *name, KConfigSkeleton *config, 
                 FaceType faceType=List, 
                 QDialogButtonBox::StandardButtons dialogButtons=QDialogButtonBox::RestoreDefaults|QDialogButtonBox::Ok|QDialogButtonBox::Apply|QDialogButtonBox::Cancel|QDialogButtonBox::Help, 
diff --git a/ksirkskineditor/ksirkcontinentdefinition.h b/ksirkskineditor/ksirkcontinentdefinition.h
--- a/ksirkskineditor/ksirkcontinentdefinition.h
+++ b/ksirkskineditor/ksirkcontinentdefinition.h
@@ -27,7 +27,7 @@
 class KsirkContinentDefinitionWidget : public QDockWidget, public Ui::KsirkContinentDefinition
 {
 public:
-  KsirkContinentDefinitionWidget(QWidget* parent) : QDockWidget(parent)
+  explicit KsirkContinentDefinitionWidget(QWidget* parent) : QDockWidget(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/ksirkcountrydefinition.h b/ksirkskineditor/ksirkcountrydefinition.h
--- a/ksirkskineditor/ksirkcountrydefinition.h
+++ b/ksirkskineditor/ksirkcountrydefinition.h
@@ -32,7 +32,7 @@
 class KsirkCountryDefinitionWidget : public QDockWidget, public Ui::KsirkCountryDefinition
 {
 public:
-  KsirkCountryDefinitionWidget(QWidget* parent);
+  explicit KsirkCountryDefinitionWidget(QWidget* parent);
 
   void initWith(const KsirkSkinEditor::Country* country);
 };
diff --git a/ksirkskineditor/ksirkgoaldefinition.h b/ksirkskineditor/ksirkgoaldefinition.h
--- a/ksirkskineditor/ksirkgoaldefinition.h
+++ b/ksirkskineditor/ksirkgoaldefinition.h
@@ -27,7 +27,7 @@
 class KsirkGoalDefinitionWidget : public QDockWidget, public Ui::KsirkGoalDefinition
 {
 public:
-  KsirkGoalDefinitionWidget(QWidget* parent) : QDockWidget(parent)
+  explicit KsirkGoalDefinitionWidget(QWidget* parent) : QDockWidget(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/ksirknationalitydefinition.h b/ksirkskineditor/ksirknationalitydefinition.h
--- a/ksirkskineditor/ksirknationalitydefinition.h
+++ b/ksirkskineditor/ksirknationalitydefinition.h
@@ -27,7 +27,7 @@
 class KsirkNationalityDefinitionWidget : public QDockWidget, public Ui::KsirkNationalityDefinition
 {
 public:
-  KsirkNationalityDefinitionWidget(QWidget* parent) : QDockWidget(parent)
+  explicit KsirkNationalityDefinitionWidget(QWidget* parent) : QDockWidget(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/ksirkskindefinition.h b/ksirkskineditor/ksirkskindefinition.h
--- a/ksirkskineditor/ksirkskindefinition.h
+++ b/ksirkskineditor/ksirkskindefinition.h
@@ -27,7 +27,7 @@
 class KSirkSkinDefinitionWidget : public QDockWidget, public Ui::skindefinition
 {
 public:
-  KSirkSkinDefinitionWidget(QWidget* parent) : QDockWidget(parent)
+  explicit KSirkSkinDefinitionWidget(QWidget* parent) : QDockWidget(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/ksirkskineditorcountriesselectiondialog.h b/ksirkskineditor/ksirkskineditorcountriesselectiondialog.h
--- a/ksirkskineditor/ksirkskineditorcountriesselectiondialog.h
+++ b/ksirkskineditor/ksirkskineditorcountriesselectiondialog.h
@@ -34,7 +34,7 @@
 class KsirkSkinEditorCountriesSelectionDialog :public QDialog, public Ui::CountriesSelectionDialog
 {
   public:
-    KsirkSkinEditorCountriesSelectionDialog(QWidget* parent) : QDialog(parent)
+    explicit KsirkSkinEditorCountriesSelectionDialog(QWidget* parent) : QDialog(parent)
     {
       setupUi(this);
     }
diff --git a/ksirkskineditor/ksirkskineditorpixmapitem.h b/ksirkskineditor/ksirkskineditorpixmapitem.h
--- a/ksirkskineditor/ksirkskineditorpixmapitem.h
+++ b/ksirkskineditor/ksirkskineditorpixmapitem.h
@@ -41,7 +41,7 @@
   /**
     * Create the window and initializes its members
     */
-  PixmapItem(QGraphicsItem* parent=0);
+  explicit PixmapItem(QGraphicsItem* parent=0);
   
   /**
     * Deletes the background and the pool
diff --git a/ksirkskineditor/ksirkskineditorscene.h b/ksirkskineditor/ksirkskineditorscene.h
--- a/ksirkskineditor/ksirkskineditorscene.h
+++ b/ksirkskineditor/ksirkskineditorscene.h
@@ -41,7 +41,7 @@
   /**
     * 
     */
-  Scene(QObject* parent=0);
+  explicit Scene(QObject* parent=0);
   Scene (qreal x, qreal y, qreal width, qreal height, QObject* parent=0);
   /**
     *
diff --git a/ksirkskineditor/ksirkskineditortextitem.h b/ksirkskineditor/ksirkskineditortextitem.h
--- a/ksirkskineditor/ksirkskineditortextitem.h
+++ b/ksirkskineditor/ksirkskineditortextitem.h
@@ -41,7 +41,7 @@
   /**
     * Create the window and initializes its members
     */
-  TextItem(QGraphicsItem* parent=0);
+  explicit TextItem(QGraphicsItem* parent=0);
   
   /**
     * Deletes the background and the pool
diff --git a/ksirkskineditor/ksirkskineditorwidget.h b/ksirkskineditor/ksirkskineditorwidget.h
--- a/ksirkskineditor/ksirkskineditorwidget.h
+++ b/ksirkskineditor/ksirkskineditorwidget.h
@@ -27,7 +27,7 @@
 class KSirkSkinEditorWidget : public QFrame, public Ui::skinEditor
 {
 public:
-  KSirkSkinEditorWidget(QWidget* parent) : QFrame(parent)
+  explicit KSirkSkinEditorWidget(QWidget* parent) : QFrame(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/ksirkspritesdefinition.h b/ksirkskineditor/ksirkspritesdefinition.h
--- a/ksirkskineditor/ksirkspritesdefinition.h
+++ b/ksirkskineditor/ksirkspritesdefinition.h
@@ -27,7 +27,7 @@
 class KsirkSpritesDefinitionWidget : public QDockWidget, public Ui::KsirkSpritesDefinition
 {
 public:
-  KsirkSpritesDefinitionWidget(QWidget* parent) : QDockWidget(parent)
+  explicit KsirkSpritesDefinitionWidget(QWidget* parent) : QDockWidget(parent)
   {
     setupUi(this);
   }
diff --git a/ksirkskineditor/mainwindow.h b/ksirkskineditor/mainwindow.h
--- a/ksirkskineditor/mainwindow.h
+++ b/ksirkskineditor/mainwindow.h
@@ -82,7 +82,7 @@
   /**
     * Create the window and initializes its members
     */
-  MainWindow(QWidget* parent=0);
+  explicit MainWindow(QWidget* parent=0);
   
   /**
     * Deletes the background and the pool