Poker, for example, is more a game of skill in the casino than it is with the LazerTron machine. Blackjack is also a game of skill. Skill is involved in betting on horses and football games. Every gambling game has an element of chance, but so does every sporting event, which is why gamblers waged one billion dollars last year in Las Vegas sports books. It is the placing of money on an outcome for some representative of value that defines gambling.
Ping pong is a game of skill.
It's when people bet on the outcome, whether the game is played live or by machine, that the sport degenerates into gambling. That it is not the nature of the game, but the wager, that constitutes gambling, was affirmed by the Nevada Attorney General in a published opinion in 1948. It is not what is in the game, but what is on the game, that matters. Under California law the question is whether the game depends predominantly upon skill or predominantly upon chance. New Jersey, where gambling is generally legal, and New York, where it is not, define two types of gambling.