This paper investigates rules of marriage in the plays of King Lear, The Way of The World, Lady Windermere's Fan, and The Browning Version. Analysis is devoted to thirteen dialogues comprising seven dialogues whose illumination reveals principles of marital sustainability in addition to six dialogues whose scrutiny shows causes of marital disruption. Thus, an overall frame of healthy marriage can be drawn based on the adoption of the principles and the obviation of the causes. The analytical, descriptive and comparative methods are applied. The researcher has found that couples intending marriage should apprehend that virtue transcends wealth and authority, courtship encompasses a rational and passionate formula, matchmaking foundations should tackle worries expected after marriage. A married couple should understand that martial sustainability is based on preservation of morality, celebration of sincerity, firm faithfulness, tolerance, and concealment of marital disruption. Marital sustainability could be also endangered due to hatred and boredom, recurrent reprimand, false appetite and fading lust, thirst for sexual gratification, undervaluation of a partner, superficial dutifulness, and spoiling a partner's moments of happiness.