private void Btn_PlayerAttack_Click(object sender, EventArgs e)
        {
            Tb_Dungeon.Clear();
            if (!_player.IsDead() && !_npc.IsDead())
            {
                int npcDamage    = _npc.Attack();
                int playerDamage = _player.Attack();
                _npc.DecreaseHealth(playerDamage);
                _player.DecreaseHealth(npcDamage);

                Tb_Dungeon.AppendText(Story.FightingNPC(_player, _npc, playerDamage, npcDamage));
                Lbl_ShowHealth.Text = _player.Health.ToString();

                if (_npc.IsDead())
                {
                    Tb_Dungeon.AppendText(Environment.NewLine + "You have defeated " + _npc.Name + Environment.NewLine +
                                          "You are rewarded with " + _npc.ExperienceDrop + " experience.");
                    _player.ExperienceGain(_npc.ExperienceDrop);
                    Pb_Experience.Value += _npc.ExperienceDrop;

                    if (Pb_Experience.Value == Pb_Experience.Maximum)
                    {
                        Pb_Experience.Value = 0;
                        RefreshMenu();
                    }
                }
                else
                {
                    Tb_Dungeon.AppendText(Environment.NewLine + _npc.Name + "'s current health: " + _npc.Health);
                }
            }
            else
            {
                MessageBox.Show("There is no enemy to attack.");
            }
        }