public class Game
{
    public readonly Deck deck;
    public readonly Card card;
    private readonly List<Player> players;
 
    public void Play1(Player p1, Card card) {
        players.Add(p1);
        this.card = card;
    }

    public void Play2(Player p1, Player p2, Card card) {
        players.Add(p1);
        players.Add(p2);
        this.card = card;
    }

    public void Play3(Player p1, Player p2, Card card, Modifier mod) {
        // todo: ...
    }

    public void Play() {
        card = null;
    }
}
