Botticelli is a game, or more accurately a pastime. It can be played by two, or by as many people as can manage to get together at the same time. It bears a vague resemblance to Twenty_questions, but there is no limit to the number of questions that can be asked.
The rules for Botticelli are similar to those given in the Wikipedia article, but in the "identity" that the "chooser" defends is usually an SF or Fantasy author, book, famous story, or well-known character in a story.
Example: Defender: I'm defending a G. Player 1: Did you change color partway through the story? Defender: No, I am not Gandalf. Player 2: Did you write a book in which the main character died in the first 20 pages? Defender (after thinking for a while): I give up. Player 2: Richard Grant (author of Tex and Molly in the Afterlife) Player 2 then asks a "direct question" (as in 20 questions): are you real or fictional? Defender: Fictional(*) Player 2 gets another turn: Did you make slow love to someone with a poor self-image? Defender: No, I am not Georges. (Georges Perrault from Friday) etc. Eventually the questioners give up. Defender: Dorothy Gale
Note: this example is considered bad form: the identity's letter should match the name the person/character is usually known by. In this case, the identity should have been a D for Dorothy. Similarly, if you are defending the SF author Cordwainer Smith, he should be under C for Cordwainer, not S for Smith and definitely not L for (Paul) Linebarger, the author's real name.
Botticelli became a thing in SF Fandom after David McDaniel had Napoleon and Ilya playing it on stakeouts in his U.N.C.L.E. books.
(*) In some variants, once the identity is narrowed (e.g., fictional in the above example), future indirect questions must be restricted to names that match what is so far known about the identity.