Михаил

public enum DamageType { Melee, Range, Magic }
public class Monster
{
    public double Health { get; private set; }
    public double MeleeDamage { get; private set; }
    public double RangeDamage { get; private set; }
    public double MagicDamage { get; private set; }
    public DamageType FavoriteDamageType { get; private set; }

    public Monster(double health, double meleeDamage, double rangeDamage, double magicDamage, DamageType favoriteDamageType)
    {
        Health = health;
        MeleeDamage = meleeDamage;
        RangeDamage = rangeDamage;
        MagicDamage = magicDamage;
        FavoriteDamageType = favoriteDamageType;
    }

    public void AttackTo(Monster monster, DamageType damageType)
    {
        switch (damageType) // используется switch
        {
            case MonsterType.Melee: monster.Health -= MeleeDamage; break;
            case MonsterType.Range: monster.Health -= RangeDamage; break;
            case MonsterType.Magic: monster.Health -= MagicDamage; break;
        }
    }

    public void AttackTo(Monster monster)
    {
        AttackTo(monster, FavoriteDamageType);
    }
}

public class Monster
{
    public double Health { get; set; }
    public double MeleeDamage { get; private set; }
    public double RangeDamage { get; private set; }
    public double MagicDamage { get; private set; }
    public IDamageStrategy FavoriteDamageStrategy { get; private set; }

    public Monster(double health, double meleeDamage, double rangeDamage, double magicDamage, IDamageStrategy favoriteDamageStrategy)
    {
        Health = health;
        MeleeDamage = meleeDamage;
        RangeDamage = rangeDamage;
        MagicDamage = magicDamage;
        FavoriteDamageStrategy = favoriteDamageStrategy;
    }

    public void AttackTo(Monster monster, IDamageStrategy damageStrategy)
    {
        damageStrategy.Attack(this, monster); // не используется switch
    }

    public void AttackTo(Monster monster)
    {
        AttackTo(monster, FavoriteDamageStrategy);
    }
}


public interface IDamageStrategy
{
    void Attack(Monster attacker, Monster defender);
}
public class MeleeDamageStrategy : IDamageStrategy 
{
    public void Attack(Monster attacker, Monster defender)
    {
        defender.Health -= attacker.MeleeDamage;
    }
}
public class RangeDamageStrategy : IDamageStrategy 
{
    public void Attack(Monster attacker, Monster defender)
    {
        defender.Health -= attacker.RangeDamage;
    }
}
public class MagicDamageStrategy : IDamageStrategy 
{
    public void Attack(Monster attacker, Monster defender)
    {
        defender.Health -= attacker.MagicDamage;
    }
}