The Lady is a Goddess who is also known as; "She-who-shall-not-be-named... The 'Million-to-One' Chance - and all of the other chances as well... The One who will desert you when you need Her the most - and sometimes She might not...". She is the Anthropomorphic personification of Lady Luck, as well as the single most powerful goddess on the Discworld, because, although She has no worshipers and the only temple ever erected to Her was destroyed purely by chance, everybody hopes and prays that She exists and that She will smile on them. Her suitors can be distinguished by their distinctive repetitive prayer; "please-oh-please-oh-please-oh-please."
Her appearance is hard to determine. After witnessing her in person, Rincewind and Twoflower were not able to agree upon what she had looked like, other than that she "appeared to be beautiful" and had green eyes - bright green, from edge to edge: no whites, no pupils, just green. In the Discworld, it is not possible for deities to change the nature of their eyes so this is likely an accurate description. She resides in Dunmanifestin on Cori Celesti with the other gods and delights in playing for the lives of the inhabitants of Discworld.
The Lady is the eternal rival of Fate. She is one of the few characters in the series who can, or has, upset Fate's powers over the board when they play games with the lives of people down on the Discworld. While Fate is implacable, The Lady is capricious: Fate plays to win, the Lady plays not to lose. Often Her playing pieces do not appear very powerful. She has never sacrificed a pawn before, or at least, so she has declared. One of Her 'favourites' appears to be Rincewind, for the simple reason that he is convinced, no matter how much evidence to the contrary, that he has survived everything simply by coincidence, or because the world hates him and that luck has played no part. Luck certainly seems to desert anyone who mentions her name. Rincewind began to say her name in The Colour of Magic but was cut short; since it began with "L", This would seem to jibe with a commonly-held superstition among gamblers that if they talk about their luck it will desert them.
While it is speculated that The Lady may possibly be the consort of Fate, this isn't too likely, given that they are bitter rivals. Given Pratchett's fondness for setting things in opposition it might also be appropriate to refer to her as "Fortune," the opposite of Fate – he cannot be cheated, but she cannot be beaten.The Lady actually shares more in common with Kaos than She does with Fate. Both Kaos and The Lady have exhibited the use of Probability in their approach to what they each do, they have even been connected with the imagery of 'a very special butterfly', also known as the 'Butterfly effect': In Interesting Times, The Lady, when She was beginning a new game against Fate, released a small butterfly from Her hand.
- The Lady is based on the Roundworld equivalent of the Ancient Roman Goddess, Fortuna, Goddess of Luck, also known as "Lady Luck"--who is the Roman counterpart of Tyche, the Ancient Greek Goddess of Luck.