diff --git a/as2/ex2/archer.cpp b/as2/ex2/archer.cpp
new file mode 100644
index 0000000..3625cee
--- /dev/null
+++ b/as2/ex2/archer.cpp
@@ -0,0 +1,165 @@
+//=======================
+//      archer.cpp
+//=======================
+#include "archer.h"
+#include <iomanip>      // use for setting field width
+#include <ctime>       // use for generating random factor
+#include <stdlib.h>
+using namespace std;
+// constructor. default values don't need to be repeated here
+archer::archer(int lv_in, string name_in)
+{
+    role=ar;    // enumerate type of job
+    LV=lv_in;
+    name=name_in;
+    
+    // Initialising the character's properties, based on his level
+    HPmax=150+8*(LV-1);     // HP increases 8 point2 per level
+    HP=HPmax;
+    MPmax=75+2*(LV-1);      // MP increases 2 points per level
+    MP=MPmax;
+    AP=25+4*(LV-1);         // AP increases 4 points per level
+    DP=25+4*(LV-1);         // DP increases 4 points per level
+    speed=25+2*(LV-1);      // speed increases 2 points per level
+    
+    playerdeath=0;
+    EXP=LV*LV*75;
+    bag.set(lv_in, lv_in);
+}
+
+void archer::isLevelUp()
+{
+    if(EXP>=LV*LV*75)
+    {
+        LV++;
+        AP+=4;
+        DP+=4;
+        HPmax+=8;
+        MPmax+=2;
+        speed+=2;
+        cout<<name<<" Level UP!"<<endl;
+        cout<<"HP improved 8 points to "<<HPmax<<endl;
+        cout<<"MP improved 2 points to "<<MPmax<<endl;
+        cout<<"Speed improved 2 points to "<<speed<<endl;
+        cout<<"AP improved 4 points to "<<AP<<endl;
+        cout<<"DP improved 5 points to "<<DP<<endl;
+        system("pause");
+        isLevelUp();    // recursively call this function, so the character can level up multiple times if got enough exp
+    }
+}
+
+bool archer::attack(player &p)
+{
+    double HPtemp=0;        // opponent's HP decrement
+    double EXPtemp=0;       // player obtained exp
+    double hit=1;           // attach factor, probably give critical attack
+    srand((unsigned)time(NULL));        // generating random seed based on system time
+
+    // If speed greater than opponent, you have some possibility to do double attack
+    if ((speed>p.speed) && (rand()%100<(speed-p.speed)))        // rand()%100 means generates a number no greater than 100
+    {
+        HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10));     // opponent's HP decrement calculated based their AP/DP, and uncertain chance
+        cout<<name<<"'s quick strike hit "<<p.name<<", "<<p.name<<"'s HP decreased "<<HPtemp<<endl;
+        p.HP=int(p.HP-HPtemp);
+        EXPtemp=(int)(HPtemp*1.2);
+    }
+
+    // If speed smaller than opponent, the opponent has possibility to evade
+    if ((speed<p.speed) && (rand()%50<1))
+    {
+        cout<<name<<"'s attack has been evaded by "<<p.name<<endl;
+        system("pause");
+        return 1;
+    }
+
+    // 10% chance give critical attack
+    if (rand()%100<=10)
+    {
+        hit=1.5;
+        cout<<"Critical attack: ";
+    }
+
+    // Normal attack
+    HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10));
+    cout<<name<<" uses bash, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
+    EXPtemp=(int)(EXPtemp+HPtemp*1.2);
+//<!-- luck
+    p.HP=(int)(p.HP-HPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
+    cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
+//<!-- luck
+    EXP=(int)(EXP+EXPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
+    system("pause");
+    return 1;       // Attack success
+}
+
+bool archer::specialatt(player &p)
+{
+    if(MP<40)
+    {
+        cout<<"You don't have enough magic points!"<<endl;
+        system("pause");
+        return 0;       // Attack failed
+    }
+    else
+    {
+        MP-=40;         // consume 40 MP to do special attack
+        
+        //10% chance opponent evades
+        if(rand()%100<=10)
+        {
+            cout<<name<<"'s leap attack has been evaded by "<<p.name<<endl;
+            system("pause");
+            return 1;
+        }
+        
+        double HPtemp=0;        
+        double EXPtemp=0;       
+        //double hit=1;         
+        //srand(time(NULL));        
+//<!-- // Luck
+        HPtemp=(int)(AP*1.2*((double)(rand() % 100 + 50) / (double)100)+20);        // not related to opponent's DP
+//-->        
+        EXPtemp=(int)(HPtemp*1.5);      // special attack provides more experience
+        cout<<name<<" uses leap attack, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
+        cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
+        p.HP=(int)(p.HP-HPtemp);
+        EXP=(int)(EXP+EXPtemp);
+        system("pause");
+    }
+    return 1;   // special attack succeed
+}
+
+// Computer opponent
+void archer::AI(player &p)
+{
+    if ((HP<(int)((1.0*p.AP/DP)*p.AP*1.5))&&(HP+100<=1.1*HPmax)&&(bag.nOfHeal()>0)&&(HP>(int)((1.0*p.AP/DP)*p.AP*0.5)))
+        // AI's HP cannot sustain 3 rounds && not too lavish && still has heal && won't be killed in next round
+    {
+        useHeal();
+    }
+    else
+    {
+        if(MP>=40 && HP>0.5*HPmax && rand()%100<=30)
+            // AI has enough MP, it has 30% to make special attack
+        {
+            specialatt(p);
+            p.isDead();     // check whether player is dead
+        }
+        else
+        {
+            if (MP<40 && HP>0.5*HPmax && bag.nOfMW())
+                // Not enough MP && HP is safe && still has magic water
+            {
+                useMW();
+            }
+            else
+            {
+                attack(p);  // normal attack
+                p.isDead();
+            }
+        }
+    }
+}
+
diff --git a/as2/ex2/archer.h b/as2/ex2/archer.h
new file mode 100644
index 0000000..3eac379
--- /dev/null
+++ b/as2/ex2/archer.h
@@ -0,0 +1,21 @@
+//=======================
+//      archer.h
+//=======================
+
+// Derived from base class player
+// For the job archer
+#include <iostream>
+#include "player.h"
+class archer : public player // subclass archer publicly inherited from base player
+{
+public:
+    archer(int lv_in=1, std::string name_in="Not Given");    
+        // constructor with default level of 1 and name of "Not given"
+    void isLevelUp();
+    bool attack (player &p);
+    bool specialatt(player &p);
+        /* These three are derived from the pure virtual functions of base class
+           The definition of them will be given in this subclass. */
+    void AI(player &p);             // Computer opponent
+    
+};
diff --git a/as2/ex2/archer.h.gch b/as2/ex2/archer.h.gch
new file mode 100644
index 0000000..09907be
Binary files /dev/null and b/as2/ex2/archer.h.gch differ
diff --git a/as2/ex2/container.h.gch b/as2/ex2/container.h.gch
index 0236601..eea46dd 100644
Binary files a/as2/ex2/container.h.gch and b/as2/ex2/container.h.gch differ
diff --git a/as2/ex2/mage.cpp b/as2/ex2/mage.cpp
new file mode 100644
index 0000000..2bda79a
--- /dev/null
+++ b/as2/ex2/mage.cpp
@@ -0,0 +1,165 @@
+//=======================
+//      mage.cpp
+//=======================
+#include "mage.h"
+#include <iomanip>      // use for setting field width
+#include <ctime>       // use for generating random factor
+#include <stdlib.h>
+using namespace std;
+// constructor. default values don't need to be repeated here
+mage::mage(int lv_in, string name_in)
+{
+    role=mg;    // enumerate type of job
+    LV=lv_in;
+    name=name_in;
+    
+    // Initialising the character's properties, based on his level
+    HPmax=150+8*(LV-1);     // HP increases 8 point2 per level
+    HP=HPmax;
+    MPmax=75+2*(LV-1);      // MP increases 2 points per level
+    MP=MPmax;
+    AP=25+4*(LV-1);         // AP increases 4 points per level
+    DP=25+4*(LV-1);         // DP increases 4 points per level
+    speed=25+2*(LV-1);      // speed increases 2 points per level
+    
+    playerdeath=0;
+    EXP=LV*LV*75;
+    bag.set(lv_in, lv_in);
+}
+
+void mage::isLevelUp()
+{
+    if(EXP>=LV*LV*75)
+    {
+        LV++;
+        AP+=4;
+        DP+=4;
+        HPmax+=8;
+        MPmax+=2;
+        speed+=2;
+        cout<<name<<" Level UP!"<<endl;
+        cout<<"HP improved 8 points to "<<HPmax<<endl;
+        cout<<"MP improved 2 points to "<<MPmax<<endl;
+        cout<<"Speed improved 2 points to "<<speed<<endl;
+        cout<<"AP improved 4 points to "<<AP<<endl;
+        cout<<"DP improved 5 points to "<<DP<<endl;
+        system("pause");
+        isLevelUp();    // recursively call this function, so the character can level up multiple times if got enough exp
+    }
+}
+
+bool mage::attack(player &p)
+{
+    double HPtemp=0;        // opponent's HP decrement
+    double EXPtemp=0;       // player obtained exp
+    double hit=1;           // attach factor, probably give critical attack
+    srand((unsigned)time(NULL));        // generating random seed based on system time
+
+    // If speed greater than opponent, you have some possibility to do double attack
+    if ((speed>p.speed) && (rand()%100<(speed-p.speed)))        // rand()%100 means generates a number no greater than 100
+    {
+        HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10));     // opponent's HP decrement calculated based their AP/DP, and uncertain chance
+        cout<<name<<"'s quick strike hit "<<p.name<<", "<<p.name<<"'s HP decreased "<<HPtemp<<endl;
+        p.HP=int(p.HP-HPtemp);
+        EXPtemp=(int)(HPtemp*1.2);
+    }
+
+    // If speed smaller than opponent, the opponent has possibility to evade
+    if ((speed<p.speed) && (rand()%50<1))
+    {
+        cout<<name<<"'s attack has been evaded by "<<p.name<<endl;
+        system("pause");
+        return 1;
+    }
+
+    // 10% chance give critical attack
+    if (rand()%100<=10)
+    {
+        hit=1.5;
+        cout<<"Critical attack: ";
+    }
+
+    // Normal attack
+    HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10));
+    cout<<name<<" uses bash, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
+    EXPtemp=(int)(EXPtemp+HPtemp*1.2);
+//<!-- luck
+    p.HP=(int)(p.HP-HPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
+    cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
+//<!-- luck
+    EXP=(int)(EXP+EXPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
+    system("pause");
+    return 1;       // Attack success
+}
+
+bool mage::specialatt(player &p)
+{
+    if(MP<40)
+    {
+        cout<<"You don't have enough magic points!"<<endl;
+        system("pause");
+        return 0;       // Attack failed
+    }
+    else
+    {
+        MP-=40;         // consume 40 MP to do special attack
+        
+        //10% chance opponent evades
+        if(rand()%100<=10)
+        {
+            cout<<name<<"'s leap attack has been evaded by "<<p.name<<endl;
+            system("pause");
+            return 1;
+        }
+        
+        double HPtemp=0;        
+        double EXPtemp=0;       
+        //double hit=1;         
+        //srand(time(NULL));        
+//<!-- // Luck
+        HPtemp=(int)(AP*1.2*((double)(rand() % 100 + 50) / (double)100)+20);        // not related to opponent's DP
+//-->     
+        EXPtemp=(int)(HPtemp*1.5);      // special attack provides more experience
+        cout<<name<<" uses leap attack, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
+        cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
+        p.HP=(int)(p.HP-HPtemp);
+        EXP=(int)(EXP+EXPtemp);
+        system("pause");
+    }
+    return 1;   // special attack succeed
+}
+
+// Computer opponent
+void mage::AI(player &p)
+{
+    if ((HP<(int)((1.0*p.AP/DP)*p.AP*1.5))&&(HP+100<=1.1*HPmax)&&(bag.nOfHeal()>0)&&(HP>(int)((1.0*p.AP/DP)*p.AP*0.5)))
+        // AI's HP cannot sustain 3 rounds && not too lavish && still has heal && won't be killed in next round
+    {
+        useHeal();
+    }
+    else
+    {
+        if(MP>=40 && HP>0.5*HPmax && rand()%100<=30)
+            // AI has enough MP, it has 30% to make special attack
+        {
+            specialatt(p);
+            p.isDead();     // check whether player is dead
+        }
+        else
+        {
+            if (MP<40 && HP>0.5*HPmax && bag.nOfMW())
+                // Not enough MP && HP is safe && still has magic water
+            {
+                useMW();
+            }
+            else
+            {
+                attack(p);  // normal attack
+                p.isDead();
+            }
+        }
+    }
+}
+
diff --git a/as2/ex2/mage.h b/as2/ex2/mage.h
new file mode 100644
index 0000000..92572db
--- /dev/null
+++ b/as2/ex2/mage.h
@@ -0,0 +1,20 @@
+//=======================
+//      mage.h
+//=======================
+
+// Derived from base class player
+// For the job mage
+#include <iostream>
+#include "player.h"
+class mage : public player // subclass mage publicly inherited from base player
+{
+public:
+    mage(int lv_in=1, std::string name_in="Not Given");    
+        // constructor with default level of 1 and name of "Not given"
+    void isLevelUp();
+    bool attack (player &p);
+    bool specialatt(player &p);
+        /* These three are derived from the pure virtual functions of base class
+           The definition of them will be given in this subclass. */
+    void AI(player &p);             // Computer opponent
+};
diff --git a/as2/ex2/mage.h.gch b/as2/ex2/mage.h.gch
new file mode 100644
index 0000000..d4ef493
Binary files /dev/null and b/as2/ex2/mage.h.gch differ
diff --git a/as2/ex2/main.cpp b/as2/ex2/main.cpp
index 8471c8e..da70dfa 100644
--- a/as2/ex2/main.cpp
+++ b/as2/ex2/main.cpp
@@ -6,10 +6,13 @@
 
 #include <iostream>
 #include <string>
+#include <cstdlib>
+#include <cmath>
 using namespace std;
 
 #include "swordsman.h"
-
+#include "archer.h"
+#include "mage.h"
 
 int main()
 {
@@ -18,6 +21,11 @@ int main()
 	cout <<"Please input player's name: ";
 	cin >>tempName;		// get player's name from keyboard input
 	player *human;		// use pointer of base class, convenience for polymorphism
+
+//<!--
+	player *enemy;  // use pointer of base class, convenience for polymorphism
+//-->
+
 	int tempJob;		// temp choice for job selection
 	do
 	{
@@ -30,6 +38,16 @@ int main()
 			human=new swordsman(1,tempName);	// create the character with user inputted name and job
 			success=1;		// operation succeed
 			break;
+//<!--
+		case 2:
+			human=new archer(1,tempName);	// create the character with user inputted name and job
+			success=1;		// operation succeed
+			break;
+		case 3:
+			human=new mage(1,tempName);	// create the character with user inputted name and job
+			success=1;		// operation succeed
+			break;
+//-->
 		default:
 			break;				// In this case, success=0, character creation failed
 		}
@@ -42,17 +60,27 @@ int main()
 		nOpp++;
 		system("cls");
 		cout<<"STAGE" <<nOpp<<endl;
-		cout<<"Your opponent, a Level "<<i<<" Swordsman."<<endl;
+//<!--
+		srand((unsigned int)time(NULL));
+		short t_s = rand() % 3;
+		cout<<"Your opponent, a Level "<<i<<((t_s == 0)?" Swordsman.":"")<<((t_s == 1)?" Archer.":"")<<((t_s == 2)?" Mage.":"")<<endl;
+
+//-->
 		system("pause");
-		swordsman enemy(i, "Warrior");	// Initialise an opponent, level i, name "Junior"
+//<!--
+		if(t_s == 0) enemy = new swordsman(i, "Warrior");
+		if(t_s == 1) enemy = new archer(i, "Warrior");
+		if(t_s == 2) enemy = new mage(i, "Warrior");
+//-->
+		
 		human->reFill();				// get HP/MP refill before start fight
 		
-		while(!human->death() && !enemy.death())	// no died
+		while(!human->death() && !enemy->death())	// no died
 		{
 			success=0;
 			while (success!=1)
 			{
-				showinfo(*human,enemy);				// show fighter's information
+				showinfo(*human,*enemy);				// show fighter's information
 				cout<<"Please give command: "<<endl;
 				cout<<"1 Attack; 2 Special Attack; 3 Use Heal; 4 Use Magic Water; 0 Exit Game"<<endl;
 				cin>>tempCom;
@@ -67,14 +95,14 @@ int main()
 					else
 						break;
 				case 1:
-					success=human->attack(enemy);
+					success=human->attack(*enemy);
 					human->isLevelUp();
-					enemy.isDead();
+					enemy->isDead();
 					break;
 				case 2:
-					success=human->specialatt(enemy);
+					success=human->specialatt(*enemy);
 					human->isLevelUp();
-					enemy.isDead();
+					enemy->isDead();
 					break;
 				case 3:
 					success=human->useHeal();
@@ -86,12 +114,12 @@ int main()
 					break;
 				}
 			}
-			if(!enemy.death())		// If AI still alive
-				enemy.AI(*human);
+			if(!enemy->death())		// If AI still alive
+				enemy->AI(*human);
 			else							// AI died
 			{
 				cout<<"YOU WIN"<<endl;
-				human->transfer(enemy);		// player got all AI's items
+				human->transfer(*enemy);		// player got all AI's items
 			}
 			if (human->death())
 			{
@@ -102,6 +130,9 @@ int main()
 				return 0;
 			}
 		}
+//<!--
+		delete enemy;
+//-->
 	}
 	delete human;//7_?????????			// You win, program is getting to its end, what should we do here?
 	system("cls");
diff --git a/as2/ex2/player.cpp b/as2/ex2/player.cpp
index 11f5437..33ea0a9 100644
--- a/as2/ex2/player.cpp
+++ b/as2/ex2/player.cpp
@@ -90,10 +90,10 @@ void player::showRole()
 		cout<<"Swordsman";
 		break;
 	case ar:
-		cout<<"Archer";
+		cout<<"  Archer ";
 		break;
 	case mg:
-		cout<<"Mage";
+		cout<<"  Mage   ";
 		break;
 	default:
 		break;
diff --git a/as2/ex2/player.h b/as2/ex2/player.h
index d1e7353..e7ab34a 100644
--- a/as2/ex2/player.h
+++ b/as2/ex2/player.h
@@ -20,6 +20,8 @@ class player
 {
 	friend void showinfo(player &p1, player &p2);
 	friend class swordsman;
+	friend class archer;
+	friend class mage;
 
 protected:
 	int HP, HPmax, MP, MPmax, AP, DP, speed, EXP, LV;
@@ -34,6 +36,9 @@ public:
 	virtual bool attack(player &p)=0;	// normal attack
 	virtual bool specialatt(player &p)=0;	//special attack
 	virtual void isLevelUp()=0;			// level up judgement
+//<!--
+	virtual void AI(player &p)=0;			// AI for robot
+//-->
 	/* Attention!
 	These three methods are called "Pure virtual functions".
 	They have only declaration, but no definition.
diff --git a/as2/ex2/player.h.gch b/as2/ex2/player.h.gch
index a08ba5b..5cb5eaf 100644
Binary files a/as2/ex2/player.h.gch and b/as2/ex2/player.h.gch differ
diff --git a/as2/ex2/swordsman.cpp b/as2/ex2/swordsman.cpp
index 44c266f..858f3a2 100644
--- a/as2/ex2/swordsman.cpp
+++ b/as2/ex2/swordsman.cpp
@@ -83,9 +83,13 @@ bool swordsman::attack(player &p)
 	HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10));
 	cout<<name<<" uses bash, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
 	EXPtemp=(int)(EXPtemp+HPtemp*1.2);
-	p.HP=(int)(p.HP-HPtemp);
+//<!-- luck
+    p.HP=(int)(p.HP-HPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
 	cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
-	EXP=(int)(EXP+EXPtemp);
+//<!-- luck
+    EXP=(int)(EXP+EXPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
 	system("pause");
 	return 1;		// Attack success
 }
@@ -119,7 +123,9 @@ bool swordsman::specialatt(player &p)
 		cout<<name<<" uses leap attack, "<<p.name<<"'s HP decreases "<<HPtemp<<endl;
 		cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl;
 		p.HP=(int)(p.HP-HPtemp);
-		EXP=(int)(EXP+EXPtemp);
+//<!-- luck
+    EXP=(int)(EXP+EXPtemp*((double)(rand() % 100 + 50) / (double)100));
+//-->
 		system("pause");
 	}
 	return 1;	// special attack succeed
diff --git a/as2/ex2/swordsman.h.gch b/as2/ex2/swordsman.h.gch
index 4504020..f15f698 100644
Binary files a/as2/ex2/swordsman.h.gch and b/as2/ex2/swordsman.h.gch differ