In the novel Stolen Diamond Ring the player will be in the role of Catherine, a young girl, in whose life an unusual adventure happened. It begins with how an old and good friend invites her to visit because of her own engagement. The guests are having fun and enjoying themselves, congratulating the owner of the mansion. Suddenly, the girl reports that her engagement ring has disappeared, although it was recently next to her.

Each guest, servant, and even the hostess and groom themselves are suspects. Perhaps someone wishes evil to the loving couple, or it is a prank. Whatever it is, the user will have to explore the environment and communicate with the characters, gradually collecting information and evidence. The information found will help solve the riddle and find out where the wedding ring went. The gameplay lasts from 2 to 10 hours of real time, depending on the decisions the gamer makes.

Katherine is trying to save her reputation as a well-wisher and a good friend. She has not touched the engagement ring and will do everything in her power to help her friend find it. Talking to various people, the user gradually receives valuable information and can notice any clues in the appearance of the interlocutor, on clothes or in pockets. Examining NPCs or exploring the surrounding locations will open access to numerous clues or pointers.