The ball must be played as it lies, except as otherwise provided in the Rules.
13-2. Improving Lie, Area of Intended Stance or Swing, or Line of Play
A player must not improve or allow to be improved:
• the position or lie of his ball,
• the area of his intended stance or swing,
• his line of play or a reasonable extension of that line beyond the hole, or
• the area in which he is to drop or place a ball, by any of the following actions:
• pressing a club on the ground,
• moving, bending or breaking anything growing or fixed (including immovable obstructions and objects defining out of bounds),
• creating or eliminating irregularities of surface,
• removing or pressing down sand, loose soil, replaced divots or other cut turf placed in position, or
• removing dew, frost or water.
However, the player incurs no penalty if the action occurs:
• in grounding the club lightly when addressing the ball,
• in fairly taking his stance,
• in making a stroke or the backward movement of his club for a stroke and the stroke is made,
• in creating or eliminating irregularities of surface within the teeing ground or in removing dew, frost or water from the teeing ground, or
• on the putting green in removing sand and loose soil or in re pairing damage.
There are 2 parts of this Rule which are broken frequently