Murder Mystery is a Roblox game where 12 people try to escape the murderer until the sheriff finds them. It's a classic parlour brought to life in Roblox. It works well because of the tense peril action combined with the need to carefully observe and communicate to find the murderer.

In each round, one player is selected to be the Sheriff, who must identify and shoot the murderer. One player is the Murderer, whose aim is to stab and kill everyone without getting shot by the sheriff. The other ten players are the Innocents who run and hide from the murderer.

Because you can't tell people's roles by looking at them you have to carefully observe what others are doing to work out whether they are the murderer. Each time someone is murdered they drop a coin that you can collect and spend between games. If the Sheriff is killed the Innocents can pick up the gun and go after the murderer themselves.

As play progresses over the repeated short rounds you have enough money to purchase different-looking knives to use when you are the murderer. This has grown into a big part of the fun, as there are hundreds of different weapons to collect with a detailed history and hierarchy of rareness for each one. This leads players to trade these items in the game, or via external websites and communities on social media.

The result is a game of nuanced social deduction where players not only need to pay attention to each other's behaviour but also use chat and other interactions to try and convince others of their innocence. It's a lot of fun without the common drive for in-game purchases. You just need to keep an eye on how and where players are trading items.