A walk-off can be recorded in many ways, including: a hit, an error, a walk with the bases loaded, a hit by pitch with the bases loaded, a sacrifice fly, an out (with less than two outs in the inning), a wild pitch, a passed ball and a balk. As long as enough runs are scored to end the game as the result of the play, it is considered a walk-off.
In walk-off situations with fewer than two outs and a runner on third base, a visiting team will typically adjust its defense to maximize the chances of stopping a runner at home plate. The visitors typically bring the infield in, so the infielders are positioned closer to home plate. Sometimes, a manager will even bring one of his outfielders into the infield to maximize the chances of throwing home for an out on a ground ball. Outfielders will almost always play very shallow to have a chance at a double play on a flyout or to throw the runner out at home on a single.