Assassins Creed Syndicate: The Dreadful Crimes is an adventure game set in 1868 London, featuring a series of intriguing missions inspired by penny-dreadful stories. Players embark on a journey to solve a string of mysterious events alongside a young Sir Arthur Conan Doyle. The gameplay introduces a new investigative style that requires players to connect clues and use their wit to uncover the truth behind these crimes.

The content includes nine individual missions, culminating in a final mission located at a significant London landmark. Successfully completing missions rewards players with exclusive gear and weapons for the protagonists, Jacob and Evie. Players can earn unique items such as a cloak for Evie and a belt for Jacob by completing five missions, or a combat cane by solving all nine, enhancing the overall gaming experience.