The classic question. The luck varies according to the emotional, philosophical, religious or mystical context of who interprets. According to the dictionary, luck is "a force without purpose, unpredictable and uncontrollable, that shapes events in a manner favorable or unfavorable to a particular individual, group or cause."
However, to imagine that there luck is to suppose that there the possibility of changing destiny, according to certain conditions that generate the events (merit for example) since that destiny is the synonym of fatality, programming or imposed by larger forces, affected by our direct or indirect action.