Would be useful to be able to add cards after the object is created.

Code:
public void addCard(WizardCard card) {
    this.cards.add(card);
}

public void addCard(int index, WizardCard card) {
    this.cards.add(index, card);
}

public void addCards(ArrayList<WizardCard> cards) {
    this.cards.addall(cards);
}

public void addCards(int index, ArrayList<WizardCard> cards) {
    this.cards.addall(index, cards);
}
Remove would be useful too.
Code:
public void removeCard(int index) {
    this.cards.remove(index);
}
(above is all untested)