Liquid Luck

• Type: Potion
• Owners: Horace Slughorn, Harry Potter
• Maker: The inventor is unknown, though the recipe is featured in advanced Potions textbooks like Advanced Potion-Making.

Liquid Luck, also known by its proper name Felix Felicis, is a potion that is the color of molten gold. When stored in a cauldron or vial, large drops are described as leaping up from the surface like goldfish, yet none of it ever spills. The potion has no described scent or taste in the novels.

Felix Felicis grants the drinker an extraordinary amount of luck for a temporary period, during which all of their endeavors are likely to succeed.

• Effect on User: The potion instills a powerful sense of confidence and an awareness of infinite opportunity. It does not create success from nothing, but rather subtly guides the user's actions through intuition, leading them along the most favorable path to achieve their goals.
• Dosage and Duration: The dosage must be carefully calculated based on the drinker's weight and the desired duration of the effect. A small vial given to Harry Potter by Professor Slughorn was said to be sufficient for approximately twelve hours of luck.
• Toxicity and Dangers: The potion is highly toxic if consumed in excess. Overdosing can lead to giddiness, recklessness, and dangerous overconfidence. It is also notoriously difficult to brew, taking six months to prepare correctly; a botched brew can have disastrous consequences.
• Restrictions: Due to its powerful and unfair advantage, Felix Felicis is banned from all organized competitions, including Quidditch matches, official examinations, and Ministry of Magic elections.

The exact origin and inventor of Felix Felicis are not detailed in the novels. It is known to be an extremely advanced and complex potion, with the recipe found in the N.E.W.T.-level textbook, Advanced Potion-Making. Professor Horace Slughorn revealed to his sixth-year Potions class that he had used the potion twice in his life, both times resulting in what he described as a “perfect day.” The first time was when he was twenty-four, and the second was at age fifty-seven.

Felix Felicis is a key plot device in Harry Potter and the Half-Blood Prince.

• Introduction and Acquisition: Harry Potter first learns of the potion in Professor Slughorn's Potions class. Slughorn offers a small vial as a prize to the student who can best brew a Draught of Living Death. Using annotated instructions from the Half-Blood Prince's copy of Advanced Potion-Making, Harry succeeds and wins the Liquid Luck.
• Retrieving Slughorn's Memory: Harry uses a small dose of the potion with the primary goal of persuading Professor Slughorn to part with his true, untampered memory regarding Tom Riddle's questions about Horcruxes. Under the potion's influence, Harry is guided to cross paths with Slughorn on his way to Hagrid's Hut for the funeral of Aragog. The potion's luck ensures the encounter is perfectly timed and that Slughorn is in an emotional state, allowing Harry to finally retrieve the crucial memory for Albus Dumbledore.
• The Battle of the Astronomy Tower: Before leaving with Dumbledore to hunt for Slytherin's Locket, Harry gives the remaining Felix Felicis to Ron Weasley, Hermione Granger, and Ginny Weasley. He instructs them to share it with Neville Longbottom and Luna Lovegood. The luck granted by the potion helps them and the other Dumbledore's Army members survive the ensuing battle with Death Eaters inside Hogwarts Castle, as they manage to avoid serious injury and fatal curses during the fight.

The name Felix Felicis is Latin. Felix means “happy,” “lucky,” or “fortunate.” Felicis is the genitive case of felix, so the name can be translated as “luck of the lucky” or “happiness of the happy,” emphasizing its potent effect. In an interview, J.K. Rowling stated that she used Felix Felicis as a plot device and a metaphor for a person's innate potential. She intentionally limited its use, explaining that if Harry had relied on it too heavily, it would have diminished the story's tension and his own accomplishments. (J.K. Rowling interview)