I think Jethro is on the money.
After first year I don't think you'll have an informed opinion as to what type of law you want to practice, rather you will start to find types of law you can't see yourself practicing.
The first bridge to cross, which I think people can do while in school and even in first year, is to decide if you are going to be happier in a solicitor role or in a litigation role.
Ultimately, its important to keep an open mind. I know people who were convinced they were going to be criminal attorneys until they spent a couple days in court and realized that they didn't have the make-up to hear the details of a lot of terrible cases.
The first opportunity to "specialize" is in second year, and even then I would recommend taking a wide range of courses.
As for switching once you start practicing, my understanding is that it is dependent upon what field you are in and where you want to switch to. The type of firm you're at also makes a pretty big difference.
If you are at a full service firm than switching will be easier since you are changing departments rather than employers. That said, if you have been writing real estate contracts for a couple of years than decide you want to become a criminal lawyer you will face some challenges. Within law there is a wide range of skill sets, what it takes to be a great commercial lawyer can be very different than what it takes to stand up in court.
As always information passed on not relating to time at Robson Hall should be treated with a grain of salt as its not first hand.
Edited by Thatguy, 19 August 2015 - 10:18 AM.