What action can lead to a one penalty stroke under the rules?

The action that leads to a one-stroke penalty involves not marking the spot before lifting the ball to identify it. According to the rules of golf, a player is required to mark the position of their ball before lifting it, even if the intention is simply to identify it. Failing to do this means the player has not followed the proper procedure, resulting in a penalty.

It's important to highlight that while certain actions on the course may raise concerns about the rules, only specific infractions incur a penalty. For example, playing a ball from the putting green is a normal part of play and does not incur a penalty as long as it is done correctly. Similarly, removing a movable obstruction carelessly is not subject to penalty as players are typically allowed to remove such items if done properly. Using equipment not allowed on the course can lead to disqualification or a more severe consequence rather than just a one-stroke penalty.