Hi riyer5, and welcome to MySwissAlps!
>> I will be staying in Lucerne from Aug 16-21. I wanted to get ideas on day trips. So far, I have the following trips in mind : Mt Pilatus, Mt Titlis, Interlaken. Any other ideas will be welcome..
Please see this page for ideas about what to see and do in Luzern:
>> I also needed to know if the Tell Pass makes sense for this trip (family of 4 : 2 adults, 2 children 16 & 12)
There is detailed information about the Tell-Pass here:
Make sure to download the map showing where the Tell-Pass is valid, and see how much of your itinerary will be covered by it.
I see you are planning to go to Interlaken. Interlaken itself has little to offer. The real attractions in that area are the lakes (Lake Brienz and Lake Thun), and the Jungfrau Region: the mountains (Jungfraujoch, Schilthorn), the mountain villages (Grindelwald, Wengen, Mürren) and the Lauterbrunnen Valley. Your Tell-Pass would get you to Interlaken, but not to any of the beautiful places in the Jungfrau Region. Furthermore, it is quite a long trip from Luzern.
If your accommodation is not finalised, you could consider breaking up your 6 days between Luzern and Interlaken (or one of the villages mentioned above).
A Swiss Travel Pass might end up meeting your transport needs better, but you will not know for sure until you have decided what trains, buses, boats and cable cars you will be using during your stay. That includes your transport between Luzern and wherever you are entering and leaving Switzerland.
This page can help you with that:
www.myswissalps.com/tr ain/ticketspasses/prac tical/chooserailpass