I have a question about trains in Italy, which came up as I recalled my England vacation last year. For that trip, I had pre-purchased point-to-point rail tickets. I missed some of my scheduled trains, and simply hopped on the next ones that came along. At each of my destinations, the employees only verified that I had purchased a ticket to their city. My question: does the internal rail system in Italy work the same way? If I purchase a ticket online from Trenitalia and miss my scheduled train, can I just ride a later one?
Yes for the normal trains. Just remember to validate your ticket in one of the yellow machines at the station before getting on board.
You can do so, so long as we are not talking Eurostars. You are buying transport from place to place
Yes if you are not on the Eurostar, EuroCity, Cisalpino or InterCity trains. These require seat reservations. The regionals and interregionals don't take reservations. You just get an open ticket. It just shows the origination and destination points and it shows either first or second class. It also shows the number of passengers as you can purchase 1 ticket for multiple people. No train number or time. Just get on as you wish after, as mentioned above, you validate your ticket in the little yellow machine. Big fine if you don't.
Of course also many Italian trains take reservations and are reservation only. So if you jump on a train you may find yourself being asked to leave your seat, I have had that happen to me several times. They have a little (on the non EuroStar trains) slot with your name on it or reserved over the seats, I'd look carefully before I got settled.
The Eurail sites can show you which trains are reservation only and the advice here about being sure to vaildate your ticket in the little yellow machine is right on.
Just a caveat for those of you using EuroStar Italia and going to Rome from Naples. If you want to get back to Rome from Naples, you might reconsider the Campi Flegrei embarkation trains as there is no elevator or escalator and in order to get to Track 4 (to Rome) you have to carry your bags down 2 flights of stairs, cross under the tracks, and carry them up two flights of stairs. If this is not an issue for you then the Campi Flegrei stop won't be either.