If your ball lands on the roof, grab a ladder and climb up and get it. A ladder has steps you use to reach up high. If you climb the corporate ladder, you’re moving up in the business world.
Some ladders are just a few feet tall, and others are taller than a house. Still others are invisible –- any time you move up in your career as a banker or NFL football player, you climb the ladder. In British English, a ladder is a run in stockings, which is funny because it usually looks like one. The superstition that it's bad luck to walk under an open ladder dates from the eighteenth century.