Train from Rome to Venice- book prior to travel?

the advantage to buying in advance is you can usually get a much lower rate. If you wait until the day of travel you'll pay the basic rate which is about 80 euros per person. If you buy in advance you can get tickets as low as 29 euros per person. These low cost tickets are non-changeable and if you miss your train they are worthless.

You should have no issues buying tickets on the day of travel. There are many trains per day between Rome and Venice. If the first train leaving is full you will be able to find seats on a later train. It's very rare that trains sell out.

donna

Advance purchasing (up to 120 days prior to travel) gives you the ability to purchase discounted tickets (SuperEconomy and Economy), which tend to sell out fast. If you wait until the day of travel or just prior, you will be left with the full fare tickets (called Base tickets). The cost of one way ticket from Rome to Venice is 80 euro (base price).
One caveat about the discounted tickets, is that once you buy them, those are non refundable and in the case of Supereconomy, not even changeable for a different time train, if you change your mind (Economy tickets may be changed, if you change your mind, but you will have to add the fare to pay full base price). Therefore if you want full flexibility, the base price gives you all the flexibility you need.

If that is what you want, then there is no reason to buy base tickets in advance. You will find seats even on the same day. During high season some trains sell out the 2nd class fare, but in that case you just have to wait for the next train (usually half hour later) or purchase a first class fare (those never sell out, even 1 min. before departure). There is an average of one to two trains every 60 min. from Rome to Venice

Carey, from Roma-Termini to Venezia-Santa Lucia, there are 20 trains a day - including Sundays. You should easily be able to buy base fare tickets at 80Euro when you arrive in Rome. Interestingly, I'm looking at Trenitalia right now for tomorrow (Sunday) and I see 80Euro tickets available for all runs. Every Economy and Super Economy ticket for all runs are gone. That could possibly mean that seats are available but you may not get 4 seats together.

Buying in advance online, the Super Economy tickets begin at 29Euro. Quite a savings. You can book as far out as 119 days (it's supposed to be 120 days but I find the 120th day showing everything as "not available"). As Roberto points out, these tickets are non-refundable and cannot be exchanged. You already know the day you will be traveling. Just decide on the train run and save 204Euro ($275) for four people. You will be planning a specific departure time for your plane tickets. It's just as easy for the train tickets. It's just one more place where you have to be on time. For $275, I'd certainly consider it.

Italo runs from Rome to Venice now too. I just used them today. Fantastic.

We just got back from Italy and used Italo and I agree with Will...fantastic!
We've done two trips in less than a year and I booked ahead for all legs of train travel. I liked the cheaper prices, the fact that we knew for sure we'd be seated together and the ability to plan my itinerary around our travel times.