When are kids free on the train?

First, two of your "kids" are not children. Persons over 14 are adults (at least in Germany). Children (14 and under) are free if they are named on their parent's ticket. That is, if you purchase a Savings Fare ticket for four adults and a child, the price is the same as it would be for just 4 adults. Same with full price point-point tickets. If you use Länder-Ticket (Bayern-Ticket, et al) you will probably only have to purchase the ticket for 4 people. The Bahn website says in many cases your own children or grandchildren under 15 are free, but to be sure, ask at the ticket counter (but buy the ticket from an automat to save 2€).

BTW, Salzburg to Munich is "completely within Germany", at least as far as German Rail is concerned (not so for Eurail). German Rail considers Salzburg Hbf, which is right across the border from German, to be a border station. German Rail passes include travel to Salzburg Hbf, as do Savings Fare tickets and the Bayern-Ticket.

Do I need to put any discount in when I am buying the Venice to Salzburg ticket for the 7 yo? It says the saver fare is 39 euro, and when I have my family & ages put in, the total price is 195 euro, which would be 5 people, with no discount for the 7 year old.

Never mind...just retried to book & the rate is 49 euro, which x 4 is 196, which is giving me free fare for the 7 yo. ;0/

Jen, if you book early on www.oebb.com, you can get fares from Venice to Salzburg for as low as 28Euro. I was just looking at them for another post. Also, my nephew took this run last fall. You depart on a bus at the Venice Tronchetto and go 3.0hrs to Villach, Austrian where you change to a train to Salzburg. Journey time is about 7.0hrs. Here's a link so see this trip in reverse (Salzburg to Venice). http://gyazo.com/24d86c32fac7e17a47a8d937de354b70