In Hit It Long an imaginary line is drawn at the flagstick, perpendicular to the line from the tee. If at any point in time a player's ball crosses the plane of that line, that player loses the hole or a betting unit.
The format of the game can be a dot format (say $1.00 per dot), skins game, match play, stroke play or other formats.
A variation of the game could be just the opposite. At some point in time the player's ball must travel past the flag.