Cluedo

Cluedo, also sometimes rendered as Cluedo?, was a board game originating on Earth.

Jamie McCrimmon told Cosmae that the Second Doctor was very fond of Cluedo. (PROSE: The Menagerie)

The Seventh Doctor had a Cluedo game from the 1930s or 1940s in Smithwood Manor. (PROSE: Cat's Cradle: Warhead)

The "ultimate bedroom" that the Eleventh Doctor had set up for Lily and Cyril Arwell included a copy of Cluedo. (TV: The Doctor, the Widow and the Wardrobe)

Mel Joseph offered to play a game of Cluedo with Ace. He later threatened her with a full-scale replica of the revolver from Cluedo, but she recognised it as a fake. (PROSE: Conundrum)

Christine Summerfield reflected that, when confronting the Horror, she could have challenged it to a game of Cluedo to finish the conflict. (PROSE: Dead Romance)

Professor Proven had a Cluedo game in his house. (PROSE: The Sleuth Slayers)

The death of Professor Gerald Peach, as noted by Donna, greatly resembled a possible murder scenario in a game of Cluedo. (TV: The Unicorn and the Wasp)

When Rhys Williams spotted that poker chips and playing cards were included in a James Bond boxset, he joked "They'll be putting Cluedo in with Poirot next". (PROSE: The House That Jack Built)

Behind the scenes
Cluedo is known as Clue in the US. A Doctor Who-themed version of the game, Clue: Doctor Who, was made by USAopoly, and features characters, locations and weapons from the series.