The phrase "be chance" means to happen by luck or coincidence. Its antonym is "be intention," which means to occur deliberately or on purpose. When something happens by intention, it is planned and has a specific goal in mind. Another antonym for "be chance" is "be design," which denotes a purposeful creation or plan. Something that is done by design is intentional and well-thought-out, as opposed to happening by chance. In short, the antonyms for "be chance" are "be intention" and "be design," both of which connote purposeful action and deliberate choices rather than random chance.