This wordless video shows how to draw a staircase in 3d. Start by drawing the steps in one dimension. Extend two lines at the top of the stairs the width you want the steps to be. Draw another line between them to make a square. This creates a landing. Draw two lines downward and parallel to the steps from the line at the top of the stairs. This will create a rail and a second base. Then extend lines from each jut of the one dimensional steps, stretching the lines alternately to the base and then to the rail to create steps. Finally, add flourishes to the side and base.