Identification of Gambling Activities

Sam Wilson often goes to the horse races, engages in his state lottery, and invests heavily in the stock of major D.S. companies. At work, Wilson is approached by his coworkers and asked to participate in a football pool. "It's totally based upon skill," his friends claim. In addition, Wilson's philanthropic club is holding a raffle in which an individual could win a new car. Are these activities gambling and therefore illegal activities?