Mature players explore the seven deadly sins as they seek fame and fortune in this Sims-style game of relationships from Monte Cristo. Throughout the game's seven chapters, which contain a total of over 60 individual missions, the player's character must use interpersonal skills to charm, intimidate, and otherwise manipulate key residents of the game's Apple City setting. By building relationships with these NPCs, players gain important information and access to new contacts, allowing them to network up the ladder of celebrity and gain even more power and influence.

Unlike in the Sims games, players take direct control of their characters in 7 Sins, steering them through more than 20 different Apple City locations and having them meet as many as 100 different NPCs. Each NPC has an individual set of wants, needs, and worries; it's up to players to learn what these are and use them to their advantage. Player characters can improve their social skills with each successful encounter, acquiring a better sense of humor, civility, culture, or other social attribute which could make future encounters even more beneficial.