Secrets and spies and everyone lies.
You go to a party but not as yourself. You're a person with secrets. Maybe you killed a man, and your past is about to catch up with you. Maybe you're a spy with ties to a foreign government. And you're a person with things to do. Find your dead sister's killer. Gather information about the shady character in the corner. You start talking to the people around you. The gorgeous lush, who isn't as drunk as she acts. The unassuming bartender, who seems to know everyone. The old friend from college you've not seen in a decade and never really trusted. These are also people with secrets and things to do. Someone screams as a body falls in the corner. Whispers about poison spread through the room. As you finish your drink, you think this is going to be a complicated night. This is Espionage Party.
In Espionage Party, players gather in one place to take on unique roles in a scenario brimming with intrigue and mystery. Talk to other players and figure out who your friends and enemies are. Keep your secrets to yourself or confide in an ally to gain their trust. Make and execute plans to complete your secret objectives but be prepared for the other players to complicate things. Even if you die, you just might keep on playing as a new character. Only the starting conditions are set in stone. What happens next and how it all turns out is entirely up to you.
Not exactly. While there are some similarities, Espionage Party differs from murder mystery games in several ways.
Murder mystery games tend to revolve around a single plot line, a murder that took place either before or at the very beginning of the party. With Espionage Party, there are a multitude of plot lines occurring simultaneously. There may or may not have been murders prior to the events of the party, and if there were, it is unlikely all the characters know about them.
With murder mysteries, the goal of players is generally to determine who the murderer was (and sometimes, for the murderer to avoid being identified). With Espionage Party, each character has a unique set of goals, which may involve investigation, but may instead involve persuasion, acquisition, murder, or other objectives.
Murder mystery games often require players to reveal information which incriminates their characters or which their characters have no in-game reason to share. This is required to be sure everyone gets the same chance to "solve" the murder. With Espionage Party, players are encouraged to share information or lie as they see fit. They will often have in-character reasons to confide in another, but they will never be required to do so.
The driving force of a murder mystery is solving the murder. The driving force of Espionage Party is freeform character interaction. Thus, while the result of a murder mystery is straightforward--the murderer is either discovered or gets away--an Espionage Party scenario can result in new surprises every time it is played, all dependent on how each character is played and how people interact.