Originally Posted by
Perche
. The only thing I'd point out is that you have to validate any train ticket that does not have an assigned seat, which is any local and some regional trains.
A local ticket is just a ticket. It doesn't have a date, time, or seat number on it. Theoretically, you could never throw it away, and use one ticket for as long as you are in Italy. That's the reason for validating it. That puts a date and time stamp on it. Then the conductor will know if you are trying to use that ticket more than once. The longer distance, more national trains have a ticket that has a date and an assigned seat on it. The conductor can see just by looking at it that you are trying to use the ticket at a time than for which it was purchased. Also, if you try to use it the following day you'd find someone sitting in your seat. So, validate any ticket that does not have an assigned seat. All others, just board.
I would add to be sure the validating machine prints a legible date and time stamp on the ticket. As dumb as it sounds, some of the machines are out of ink.
Coming out of Firenze, the validation machine put the nick in my ticket, with no date/time. I didn't like that, at all. wrote the date/time of departure, in ink, on the ticket. I saw several people get banged 50 Euro each for having either an non validated or not legibly stamped ticket in the coach I was in. Conductor actually came back for my ticket to show them what to do next time, but still fined each of them. On the Regionales, it's almost guaranteed the fine will exceed the cost of the ticket!