How can i make fields and methods of a sub class usable to a class which only uses the super class through another class

So, after some hours searching through the forum for the answer i am searching for i couldn't find anything that helps me so here i go.

I am trying to make a Monopoly style game and i am making the Game Engine class.
I have a 'Board' class and an 'abstract Card' class which i use to make several other classes such as 'HouseCard', 'Decision Card', 'AirportCard' etc.
As you can see every card class has different methods and fields.
I am trying to make the game engine class right now and i need to access some of the fields and some of the methods of some of those classes but i can't. The only possible solution Eclipse gives me is to make the methods inside the 'Abstract Card' class and the do an @Override in the sub classes but this is not right because i will have to implement those methods inside all other classes so in the end i will have like 30 methods in every class which is wrong.
I am providing some code to see what i mean because i have done this solution to two abstract Boolean methods and one int and already it feels wrong.

This is the Card class:

public abstract class Card {
public Card() {
}
public void stringCard() {
}
public void setHolder(int holderID) {
}
public abstract Boolean hasOwner();
public abstract Boolean buyable();
public abstract int getBuyCost();
}

This is the one of the card sub classes i use 'HouseCard' class:

public class HouseCard extends Card{
public String cardName;
public int buycost, rent, h1, h2, h3, h4, hotel, mortgage, hcost;
public int holderID = -1;
public HouseCard(String cardName, int buycost, int rent, int h1, int h2, int h3, int h4, int hotel, int mortgage, int hcost) {
this.cardName = cardName;
this.buycost = buycost;
this.rent = rent;
this.h1 = h1;
this.h2 = h2;
this.h3 = h3;
this.h4 = h4;
this.hotel = hotel;
this.mortgage = mortgage;
this.hcost= hcost;
}
@Override
public void setHolder(int holderID) {
this.holderID = holderID;
}
@Override
public Boolean buyable() {
if (this.holderID == -1) {
return true;
}
else {
return false;
}
}
@Override
public Boolean hasOwner() {
if (this.holderID == -1) {
return false;
}
else {
return true;
}
}
@Override
public int getBuyCost() {
return buycost;
}
@Override
public void stringCard() {
System.out.println("      " + cardName + " (" + buycost + "$)");
System.out.println("");
System.out.println("Rent Pay    -> " + rent + "$");
System.out.println("1st House   -> " + h1 + "$");
System.out.println("2nd House   -> " + h2 + "$");
System.out.println("3rd house   -> " + h3 + "$");
System.out.println("4th house   -> " + h4 + "$");
System.out.println("");
System.out.println("Hotel       -> " + hotel + "$");
System.out.println("");
System.out.println("Mortgage    -> " + mortgage + "$");
System.out.println("");
}
public String getCardName() {
return cardName;
}
}

And this is the board class i use to store every square in my game using different methods for different cards:

public class Board {
public ArrayList<Card> Cards;
public int numberBoard = 0;
public Board(){
this.Cards = new ArrayList<Card>();
}
public void addCard(String cardName, String cardDesc) {
Card card = new GeneralCard(cardName, cardDesc);
Cards.add(card);
numberBoard++;
}
public void addCard(String cardName, String cardDesc, Action action) {
Card card = new GeneralCard(cardName, cardDesc, action);
Cards.add(card);
numberBoard++;
}
public void addCardMulti(String cardName, int buycost, int pay1, int pay2, int mortgage) {
Card card = new MultiCard(cardName, buycost, pay1, pay2, mortgage);
Cards.add(card);
numberBoard++;
}
public void addCardAirport(String cardName, int buycost, int air1, int air2, int air3, int air4, int mortgage) {
Card card = new AirportCard(cardName, buycost, air1, air2, air3, air4, mortgage);
Cards.add(card);
numberBoard++;
}
public void addCardHouse(String cardName, int buycost, int rent, int h1, int h2, int h3, int h4, int hotel, int mortgage, int hcost) {
Card card = new HouseCard(cardName, buycost, rent, h1, h2, h3, h4, hotel, mortgage, hcost);
Cards.add(card);
numberBoard++;
}
}

And here are some lines i have to use fields and methods from the sub classes Cards. As you can see in the first line where i use the abstract method getBuyCost() it works fine but at the second line where i use getCardName(), which is a method used in the sub class only without having it in the Card super class it doesn't work.

dashboard.Cards.get(Players.get(i).getSquare()).getBuyCost();
System.out.println(Players.get(i).getName() + " bought " + dashboard.getCard(Players.get(i).getSquare()).getCardName() + " successfully.");

How can i fix this?

First, you should set HouseCard attributes as private, if you want to respect encapsulation and use your accessor methods.

Second, remember to share all the code related so we can help you better. I will assume Players.get(i).getSquare returns an instance of HouseCard in your code.

And finally, if square attribute is type of Card, you will need to make cast of HouseCard before calling the getCardName() method.

You will end up having something like this:

HouseCard card = (HouseCard) Player.get(i).getSquare();
String cardName = card.getCardName();

Your issue is that the getCardName() method is not defined in your Card class. Since that variable seems like data that would apply to all your subclasses I recommend moving it up into the parent Card class.

public abstract class Card {
private String cardName;
public Card(String cardName) {
this.cardName = cardName;
}
public String getCardName() {
return cardName;
}
//Other methods
}

Then your subclasses can call the super() method to set that value when they are instantiated.

public class HouseCard extends Card {
public HouseCard(String cardName) {
super(cardName);
}
}

And then you won't have any issues calling the getCardName() method on a Card object since you defined what that is in the Card parent class. You can also then call the getCardName() method inside your subclasses to get the value in this context (or use the protected keyword instead of private for the variable if you wanna just reference it directly).

@Override
public String toString() {
return getCardName() + " some other info specific to this class"; 
}