In Harry Potter and the Half-Blood Prince, Felix Felicis is the potion that gives Harry exceptional luck.
Harry wins a small bottle of Felix Felicis in Professor Slughorn’s first Potions lesson by producing the best Draught of Living Death. The potion is commonly called Liquid Luck because it temporarily makes the drinker unusually fortunate.
Harry later drinks Felix Felicis before visiting Hagrid and persuading Professor Slughorn to provide an important memory about Tom Riddle. His confidence and timing improve, although the potion does not give him unlimited power or guaranteed success.
Felix Felicis is different from Amortentia, the powerful love potion, and Polyjuice Potion, which changes a person’s appearance. The potion’s gold colour and limited duration help distinguish it from other magical brews shown in the films.