This is a domino method I created myself. It is called the plank method. How you make it is you first make a domino bridge by putting two dominos on the ground flat, next to each other and then putting a domino in the middle on the top of them both. Add another on to the side, and repeat. Then after is is 5 or 6 dominos high, put a domino on the top, sideways. It should jab out. Then line up your dominos so that a domino will knock in to it on 1 side, the domino sticking out should pop over and hit another domino on the other side.