Train Reservations for Berlin and travels south to Bavaria?

None of those trains require reservations and the legs by regional train don't take reservations. If the train does get crowded, you can still board and wait a bit for a seat to open up (while doing your best to look like tired seniors). For legs served by InterCity and InterCity Express trains, optional seat reservations cost €4 per person, available at stations or on the DB web site and that would be the best way to get seats somewhat together for 8 people. For instance, Berlin-Erfurt trains depart about hourly and are reserve-able, if you're ready to choose a departure time. When you start your online booking, check the box "Reservation for seat only."

Thank you so much, Laura. We are not traveling on Fridays or Sundays (Sept.) which I think are not busy days. My husband says he will carry a cane!

If you're traveling through Munich during Oktoberfest, you may want to get seat reservations for legs of the trip around the city, where possible. You don't need to buy them far in advanced, just get them at the station at least a few hours before you travel.

The main reason to get reservations is not to guarantee a seat... except on some very busy days, you can almost always find one. The reason is so that you don't have to fumble around walking from carriage to carriage trying to locate a vacancy. With a reservation, you know which carriage you need to enter (the information boards and monitors will tell you where to stand on the platform), and when the train stops, you can procede directly to your waiting seat.

Danke Tom. We will buy reservations around Munich especially the ICE from Nurnberg to Munich during Oktoberfest. Plus, we are now aware and will check it out at the train stations beforehand. Really looking forward to our trip riding the rails on those wonderful high speed trains. Again, Danke!