Gambling is the betting or staking of something of value, with consciousness of risk and hope of gain, on the outcome of a game, a contest, or an uncertain event whose result may be determined by chance or accident or have an unexpected result by reason of the bettor’s miscalculation.| Encyclopedia Britannica
World War I (1914–18) was an international conflict that embroiled most of the nations of Europe along with Russia, the U.S., the Middle East, and other regions. It led to the fall of four great imperial dynasties and, in its destabilization of European society, laid the groundwork for World War II.| Encyclopedia Britannica