Step on Line -- Legal or Illegal?

[Nevadaref]

Originally Posted by Juulie Downs

I'm wondering if there's an equally simple, elegant way to describe all the different line violations. The boundary lines are all out of bounds, so if a person is throwing in, it's legal to step on the line, but the lines around the top of the key, where the shooter stands, are all not okay. Free throw lane lines are not okay to step on, during the free throw, stepping on the 3-point line makes a shot a 2-point shot. So basically all lines are like oob, except that the division line is legal if you're still in backcourt. To me, it's confusing. Anyone help here?

When I was first taught the rules in my initial officiating class, the instructor stated that if a player is touching any line on the court, the player is within the area defined by that line.

For example, if a player is touching a boundary line the player is OOB.
If a player is touching a lane line, the player is within the FT lane.
If a player is touching the 3pt arc, the player is inside the 3pt area.
If a player is touching the division line that player is within the backcourt.
Touching the FT semi-circle puts the player within the area allowed for the free-thrower.

Perhaps someone can phrase it more smoothly in a single sentence, but that is the gist of it.