In Texas, like many states, raffles are considered gambling/games of chance and therefore regulated by state law.
Exactly WHAT all is classified as a raffle could be open to interpretation. But the class activity of selling advance tickets for a large prize where one winner is drawn at a later date is definitely a raffle. In that case, you do need to be careful to follow state law.
In other instances it's less clear - like doorprize raffles or bag raffles where, for instance, you sell $1 tickets at the door of an event and then each person puts their tickets in the containers for the prizes they want to try for. I asked for a ruling on that from the OAG and was told to consult a private lawyer.
I don't know that it's illegal to use the term "raffle", but that implies it
is a rafflle and therefore you should be following the raffle regulations. In our case, we do a lot of the lesser activities and try to stay away from the term "raffle", just to distance ourselves further from those regulations.
As far as a "real" raffle - there isn't any registration or fees (in Texas), but you have to follow the rules.
Here's some more information
Texas Attorney General