Mad Libs is a word game where players fill in the blanks of a story with various parts of speech, such as nouns, verbs, and adjectives. The game typically starts with a story template that has missing words, and players provide their own words without knowing the context. Once all the blanks are filled, the completed story is read aloud, often resulting in humorous and nonsensical outcomes. This game is popular among friends and families, making it a fun activity for gatherings or road trips. Mad Libs can also be used as an educational tool to help improve vocabulary and understanding of grammar in a playful way.