Dasharatha owed Kaikeyi two boons, not three. When she finally collected on that battlefield debt, she shattered a dynasty.
She had earned them fighting alongside him years earlier. When the gods sought Dasharatha's assistance in their war against the demon king Timidhvaja, also known as Sambara, Kaikeyi accompanied her husband to the front lines. During a brutal clash, Dasharatha was struck unconscious by enemy weapons. Acting swiftly, Kaikeyi took the reins of the chariot, navigated through the chaos, and steered him to safety, where she tended his wounds. When Dasharatha revived and realized his queen had saved his life, he offered her two wishes on the spot. Kaikeyi accepted the offer with gratitude but chose to defer them, confident in her husband's love and seeing no immediate need for royal favors.
The debt remained dormant until the eve of Prince Rama’s coronation. Spurred by her scheming maid Manthara, who convinced her that Rama’s ascension would reduce Kaikeyi and her son Bharata to servants, the queen retreated to the kopabhavan, the royal sulking chamber. When Dasharatha arrived to console her, she invoked his solemn oath and demanded her two boons.
The first boon was that her son, Bharata, be anointed regent and crowned king of Ayodhya. The second was that Rama be banished to the Dandaka forest for fourteen years, living the life of an ascetic clad in tree bark and deer skin.
Kaikeyi chose fourteen years deliberately. Under ancient legal conventions of the era, an exile spanning fourteen years was considered long enough to formally sever an heir's customary claim to the throne, ensuring that Bharata’s rule would be permanently consolidated. Dasharatha was shattered, yet the unbending code of the Ikshvaku dynasty forbade breaking a royal pledge. Rama willingly accepted the sentence to preserve his father's honor, setting in motion the fourteen-year exile that frames the rest of the epic.