Thread: NullPointerException?

I've got a lot of code, and I'm not entirely sure what I've done wrong. My IDE isn't showing any errors, but I've got NullPointerExceptions in three of my classes.

What should I do?

Exception in thread "main" java.lang.NullPointerException
at rpgtxt.Player.getBlock(Player.java:71)
at rpgtxt.Battle.mAttack(Battle.java:59)
at rpgtxt.Battle.bMain(Battle.java:14)
at rpgtxt.Main.main(Main.java:83)

Player Class :

package rpgtxt;
import java.util.*;
 
public class Player {
 
	public int hp;
	public int hptotal;
	public int dmg;
	public int str;
	public int intlg;
	public int will;
	public int xp;
	public int lvl;
	public int block;
	public String pCls;
	public boolean isAlive;
 
	public String pName()
	{
		Scanner scn = new Scanner(System.in);
		String ans = scn.nextLine();
		ans = pCls;
		return ans;
	}
 
	public String pClass()
	{
		Scanner scn = new Scanner(System.in);
		String ans = scn.nextLine();
		return ans;
	}
 
	public int getHP()
	{
		hp = getLVL() * 25;
		return hp;
	}
 
	public int getLVL()
	{
		int xp_total = xp;
		if (xp_total >= 110000)
		{
			lvl = 5;
			return lvl;
		}
		else if (xp_total >= 75000)
		{
			lvl = 4;
			return lvl;
		}
		else if (xp_total >= 45000)
		{
			lvl = 3;
			return lvl;
		}
		else if (xp_total >= 20000)
		{
			lvl = 2;
			return lvl;
		}
		else
		{
			lvl = 1;
			return lvl;
		}
 
	}
 
	public int getBlock()
	{
		if (pCls.equalsIgnoreCase("Warrior"))
		{
			block = str - 10;
		}
		else if (pCls.equalsIgnoreCase("Rogue"))
		{
			block = will - 10;
		}
		else if (pCls.equalsIgnoreCase("Wizard"))
		{
			block = intlg - 10;
		}
 
		return block;
	}
 
 
 
}

Main Class:

package rpgtxt;
import java.util.*;
 
public class Main {
 
	public static void main(String[] args)
	{
		Scanner in = new Scanner(System.in);
		Player player = new Player();
		int lvldsp = player.getLVL();
		System.out.println("Hello. What's your name?");
		String Name;
		Name = player.pName();
		System.out.println("Ah... " +Name+ ". Are you a rogue, warrior, or wizard?");
		String Class = player.pClass();
		int clsslct = 1;
		while (clsslct == 1)
		{
			if (Class.equalsIgnoreCase("Rogue"))
			{
				player.str = 5;
				player.intlg = 10;
				player.will = 15;
				clsslct--;
			}
			else if (Class.equalsIgnoreCase("Wizard"))
			{
				player.str = 5;
				player.intlg = 15;
				player.will = 10;
				clsslct--;
			}
			else if (Class.equalsIgnoreCase("Warrior"))
			{
				player.str = 15;
				player.intlg = 5;
				player.will = 10;
				clsslct--;
			}
 
		}
		System.out.println("The path of the " +Class+ " is a noble one.");
 
		if (Class.equalsIgnoreCase("Warrior"))
		{
			System.out.println("Here's a sword.");
			System.out.println("You received: Wooden Sword! Str + 1");
			Item wsword = new Item();
			wsword.iStr = 1;
			player.dmg = 1 + wsword.iStr + player.str;
			wsword.iName = "Wooden Sword";
			System.out.println("Your damage is now "+player.dmg);
		}
		else if (Class.equalsIgnoreCase("Rogue"))
		{
			System.out.println("Here are two daggers.");
			System.out.println("You received: Wooden Daggers! Will + 1");
			Item wdags = new Item();
			wdags.iWil = 1;
			player.dmg = 1 + wdags.iWil + player.will;
			wdags.iName = "Wooden Daggers";
			System.out.println("Your damage is now "+player.dmg);
		}
		else if (Class.equalsIgnoreCase("Wizard"))
		{
			System.out.println("Here's a staff.");
			System.out.println("You received: Wooden Staff! Int + 1");
			Item wstaff = new Item();
			wstaff.iInt = 1;
			player.dmg =  1 + wstaff.iInt + player.intlg;
			wstaff.iName = "Wooden Staff";
			System.out.println("Your damage is now "+player.dmg);
		}
 
		System.out.println("Now that you have a weapon, are you prepared for your first battle?");
		String fBattle;
		fBattle = in.nextLine();
		if (fBattle.equalsIgnoreCase("yes"))
		{
			Monster fMon = new Monster();
			fMon.mName = "Zombie";
			Battle rBattle = new Battle();
			rBattle.bMain(player, fMon);
		}
 
 
		if (player.isAlive = false)
		{
			System.out.println("Game over!");
		}
	}
 
}

Battle Class:

package rpgtxt;
import java.util.*;
 
public class Battle {
 
	public void bMain(Player player, Monster monster)
	{
		Scanner keyIn = new Scanner(System.in);
		System.out.println("A " +monster.mName+ " has attacked!");	
		do
		{
			wrAttack(player, monster);
			keyIn.nextLine();
			mAttack(player, monster);
 
		} while(player.hp > 0 && monster.hp > 0);
 
	}
 
	public void wrAttack(Player player, Monster monster)
	{
		Scanner keyIn = new Scanner(System.in);
		System.out.println("You attack!");
		Random roll = new Random();
		int rvalue = roll.nextInt( 21 );
		int mBlock = monster.getBlock(player);
		System.out.println(monster.mName+" has "+monster.hp+" hp.");
		keyIn.nextLine();
		if (rvalue == 20)
		{
			System.out.println("Critical hit!");
			monster.hp = monster.hp - (player.dmg * 2);
			System.out.println(monster.mName+" has "+monster.hp+" hp.");
			player.xp = player.xp + 1000;
			keyIn.nextLine();
		}
		else if (rvalue > mBlock)
		{
			System.out.println("You strike!");
			monster.hp = monster.hp - player.dmg;
			System.out.println(monster.mName+" has "+monster.hp+" hp.");
			player.xp = player.xp + 500;
			keyIn.nextLine();
		}
		else if (rvalue < mBlock)
		{
			System.out.println("You miss!");
			keyIn.nextLine();
		}
 
	}
 
	public void mAttack(Player player, Monster monster)
	{
		Scanner keyIn = new Scanner(System.in);
		System.out.println(monster.mName+" attacks!");
		Random roll = new Random();
		int rvalue = roll.nextInt( 21 );
		int block = player.getBlock();
		System.out.println("You have "+player.hp+" hp.");
		keyIn.nextLine();
		if (rvalue == 20)
		{
			System.out.println("Critical hit!");
			player.hp = player.hp - (monster.dmg * 2);
			System.out.println("You have "+player.hp+" hp.");
			keyIn.nextLine();
		}
		else if (rvalue > block)
		{
			System.out.println(monster.mName+" strikes!");
			player.hp = player.hp - monster.dmg;
			System.out.println("You have "+player.hp+" hp.");
			keyIn.nextLine();
		}
		else if (rvalue < block)
		{
			System.out.println(monster.mName+" misses!");
			keyIn.nextLine();
		}
	}
}

Any help is appreciated!