In the "semi-barbaric kingdom" created by Frank Stockton in "The Lady or the Tiger?" a young man who did not have royal blood (a commoner) dared to do what no one else had done--he loved the princess. When the king determined that the young lover's fate was to be decided in the arena, the princess did what no one else had ever done--she discovered the "secret of the doors."

The arena is the place in which all matters of justice are impartially decided in this kingdom. Every young man sent into the arena is the master of his own fate, as he may choose either of the two doors which face him. Behind one is the fiercest (and hungriest) tiger in the land who will immediately attack and eat the man if the tiger's door is opened. Behind the other door is the most beautiful woman in the land, and if her door is opened the young man will immediately be married to her. 

The princess's lover, like all the other men who have come to the arena before him, must choose one of the doors. When he walks into the arena, he does not even look at the doors; the only thing he looks at is the princess, for he knows without a doubt that she has discovered the secret of the doors.

The semi-barbaric princess is there not only to see but to decide her lover's fate in the arena. If she directs him to one door, her lover will become another woman's husband; if he opens the other, her lover will be eaten alive. Neither option is acceptable to her, yet one of them will happen and she has determined that she must be the one to control her lover's fate.

From the moment that the decree had gone forth that her lover should decide his fate in the king's arena, she had thought of nothing, night or day, but this great event and the various subjects connected with it. Possessed of more power, influence, and force of character than any one who had ever before been interested in such a case, she had done what no other person had done - she had possessed herself of the secret of the doors. [G]old, and the power of a woman's will, had brought the secret to the princess. 

Two things, then, allowed the princess to learn behind which door was the lady and behind which door was the tiger: money (in the form of gold) and her semi-barbaric and determined will. She purposed to do what had never been done, and she did it. We can speculate that the princess learned who the keeper of the secret was (probably not a particularly difficult task) and then wore him down with her persistence and the enticing offer of a substantial bribe. Stockton implies that it was not a simple task when he references "the power of a woman's will," but she succeeded in her goal.

The much more difficult thing for the princess to do, though, is decide which door she should send her lover to open.