Walk-ons are expected to be part of the team in all ways. They are held to the same standards, train as though they are going to compete, and participate in team events. They don't all travel - a team can only travel with a maximum of 16- 18 girls in D1 (can't recall which). Depends on how many walk-ons the team has. Some teams like to have a lot and some have few, and my guess is it really depends a lot on the team budget including how far the team typically has to travel (fly trips are expensive)! Some do end up competing, some don't. From talking to several colleges and knowing a few girls, I would say that a team is not going to offer you a walk-on spot unless they can reasonably expect you to have comparable skills to their scholarship athletes (and therefore be able to make a line up) in at least one (or more) event. The higher ranked the team, the more they will expect of their walk-ons.