The basic 'dominoes' described in the previous step are all you need for a domino topple. Now we will show you some additions that you can add to enhance appeal. You can make a staircase as shown in the image on the right. The process is relatively straightforward: we used the same strips used for the basic 'dominoes' but cut them to different lengths to create the staircase. One long piece is used as the base, and then two different sized pieces create the stairs themselves: 1" (25mm) and 2" (50mm) long. We joined them with a small amount of polyurethane glue and supplemented this with brad nails.

We put a 1 1/2" (38mm) wooden ball on the top step by drilling a shallow 1/2" (13mm) diameter hole with a forstner bit. This hole holds the ball in place but allows it to escape when struck by a domino. You can also use a domino on the top step and have it fall on a line of dominoes strategically placed below, or you can use the device shown in step 4. As you can see from the image on the right, using the dimensions for the staircase that we listed above yields an appealing feature: the dominoes remain on their respective steps even after toppling. We chose a cantilevered design because it is visually interesting, but you can include a vertical support to strengthen the staircase.