Tar was used on the basement steps in The McCallister House. The tar was intended to cause the person the inconvenience and annoyance of losing their footwear and socks. Also the possibly to get stuck in place. Also to increase the inconvenience, Kevin used it to glue a nail in place. Marv, slowly and painfully walked through this tar and soon ended up with tar covered bare feet. Then he painfully stepped on the nail and fell down backwards onto the floor below.