In Scotland Yard, one of the players takes on the role of Mr. X. His job is to move from point to point around the map of London taking taxis, buses or subways. The detectives – that is, the remaining players acting in concert – move around similarly in an effort to move into the same space as Mr. X. But while the criminal's mode of transportation is nearly always known, his exact location is only known intermittently throughout the game.

The 125 fare tickets are 5 black, 23 pink underground, 43 green bus, 54 yellow taxi.
One player controls 'Mr. X': a criminal whose location is only revealed periodically throughout gameplay. The other players each control a detective, all of which are always present on the board.

All players start with a number of tokens ("tickets") which each allow them to use one of the following methods of transport:
Taxis, allow the player to move only one space peruse but can be used on most spaces in the game to move in all directions.
Buses, which are available throughout most of the board and allow longer-distance travel but only if the player is located at a bus station.
The Underground allows quick, long-distance travel between stations that are long distances from each other and can therefore be used to move towards Mr. X if he turns out to be a long-distance away.
Ferries, which only Mr. X can use with a black tile, allow him to follow routes along the River Thames between Greenwich and Whitehall.
All players draw one of 29 possible cards, each with a starting location on the back, to which the player must move their token. Mr. X always draws first and doesn't share where he is starting with the detectives. The locations on the cards are spaced far enough apart to ensure that Mr. X cannot be caught in the first round of play. There are a total of 199 spaces ("stations") on the board.
Each detective begins with a total of 23 transport tickets: 11 taxi tickets, 8 bus tickets, and 4 Underground tickets. Once each transport token is used by a detective, it is turned over to Mr. X, effectively giving him an unlimited amount of transport tokens. For each move that Mr. X makes, he writes down his destination. The game comes with a "travel log" and paper inserts to be used with it, on which Mr. X can write this. After making a note of his location, Mr. X covers it with the ticket that he has used to move there, giving the detectives a clue as to his whereabouts.

Mr. X also has a supply of black tokens (one per detective in play or always five in the Milton Bradley version) that can be used in place of any other kind of transport ticket but prevents the type of transport from being visible, and three tokens that allow him to make two moves in a single round. The water routes require a black ticket to use and so when one of
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