while(true)
{
    cout << description.c_str() << "nn";
    int response = 0;
    do
    {
        cout << "What would you like to do?n";
        if(enemy)
        cout << "1) Attack the evil "
             << enemyName.c_str() << "n";
        else if(!enemy)
        cout << " 1) Move to the next room.";
        if(treasure)
        cout << " 2) Pick up the "
             << treasureName.c_str() << "n";
        cin  >> response;
    }while(response < 1 || response > 2);

    switch(response)
    {
        case 1 :  if(enemy)
                  {
                    enemy = !enemy;
                    cout << "You slay the deadly "
                         << enemyName.c_str() << "n";
                  }
                  else if(!enemy)
                    return;
                  break;
        case 2:   treasure = !treasure;
                  cout << "You pick up the "
                       << treasureName.c_str() << "n";
                  break;
    }
}

return;

if(enemy)
{ ...
}
else if(!enemy)
{...
}

case 2:   treasure = !treasure;
              cout << "You pick up the "
                   << treasureName.c_str() << "n";