Felix Felicis

Felix Felicis (Fee-LICKS Fi-li-siss) is the name of a fictional potion in the book Harry Potter and the Half-Blood Prince that grants temporary good luck to the drinker. The name, like many things in the Harry Potter novels, is Latinate in origin, and translates to "lucky of lucky," or "happy of happy." ("happy", strictly speaking, means "lucky.")

A chapter of Half-Blood Prince is titled "Felix Felicis," and this was one of three chapter titles revealed prior to the book's release; this was possibly done as a kind of red herring, as many people were suspecting it to refer to a character, as "Felix" can also be used as a name.

The Potion
The potion is supposedly extremely difficult to brew, requiring six months of preparation and time to stew properly. In addition, it can all too easily fail, resulting in a potion with dangerous consequences.

The potion looks like molten gold, and when it is put to boil, drops of the potion fly upward, but not a single drop is spilled.

Having too much of the potion is like having "too much of a good thing," and the drinker experiences, as Professor Slughorn describes, "giddiness, recklessness, and dangerous overconfidence."

Felix Felicis is also banned from all competitive events i.e. elections, sports, contests etc.

The potion's means coincide with Rowling's own personal philosophy. When asked on her website whether or not she believes in fate, Rowling responded, "No, I believe in hard work and luck, and that the first often leads to the second." Rowling feels that Felix best exemplifies this philosophy, as it is the user's confidence in himself that leads to his being "lucky."

Half-Blood Prince
In the novel Harry Potter and the Half-Blood Prince, Potions professor Horace Slughorn has brewed a cauldron and offers a small bottle, good for twelve hours of luck, to the winner of an in-class Potions-brewing contest. Harry Potter wins the contest with help from the notes in his textbook, that is supposed to have belonged to the Half-Blood Prince previously.

Harry pretends to spike his friend Ron Weasley's cup with the potion before a Quidditch match, resulting in confident playing from Ron, who believes himself to be lucky. (A prime example of the placebo effect, this is also much like the use of the "Magic Feather" in Dumbo.) Harry is tempted not to use the potion because he has hopes for it that show some of his true colors when it comes to Ginny. He secretly hopes to use it to have Dean and her break up and daydreams that they will then get together. Harry uses up a quarter of the Felix Felicis to persuade Professor Slughorn to give him the memory that he had tampered with, inadvertently breaking Ginny Weasley (his secret crush) up with her boyfriend, Dean Thomas, and also his best friend Ron Weasley up with his girlfriend Lavender Brown (whom he had gotten very tired of).

Before departing with Albus Dumbledore to find a Horcrux, Harry gives the remainder to Ginny Weasley, Ron Weasley and Hermione Granger in order to give them luck when facing Draco Malfoy's scheme. This proves to be fortunate in itself, as they manage to confront several Death Eaters but are not seriously hurt. Afterwards, they directly attribute their survival to the potion.

It seems apparent that Felix Felicis can make your hopes for the potion work in a very small amount of time. For instance, Harry has the inclination to use the potion to get Ginny to fall for him and Ron to break up with Lavender, however when he drank the potion he was concentrating on getting the memory from Professor Slughorn. In a matter of a few minutes, by becoming invisible and letting Lavender see only Ron and Hermione coming down from the boys dormitory and brushing between Ginny and Dean, making Ginny think that Dean had helped her to get through the portrait hole one too many times, a habit which she finds annoying, Harry has achieved two of his goals while on the way to getting the third.

Felix felicis