Felix Felicis, also called Liquid luck, is a potion that grants whoever drinks it unusually good luck. The time span depends on how much is imbibed. It is banned in all sporting events, competitions and examinations. It looks like gold in fluid form. According to Horace Slughorn, excessive consumption results in side effects that include giddiness and overzealousness, among other effects related to overconfidence. In Half-Blood Prince, Harry pretends to give some to Ron so that he will do well at Quidditch. Ron's luck turns for the better, with the confidence working as a placebo. Harry uses most of it in order to extract memories from Slughorn about Tom Riddle and Horcruxes, and the rest is shared between Ron, Hermione, Neville and Ginny the night Death Eaters break into Hogwarts.