Interaction with a location is caused by a movement of the player's merchant, but it is exactly this movement where the tricky and innovative character of Istanbul becomes visible. For one, a merchant only has a maximum movement allowance of two locations, so that the gameboard of 4 times 4 locations cannot be crossed in a single turn. However, it is not even enough to move a merchant to the desired location, but the player also must have an assistant available which will help the merchant to perform an action at the location. At the beginning of the game each merchant starts with four assistant tokens at the central Fountain location, and the assistants will be moved together with the merchant. However, when the merchant reaches a location which the player wants to use, he has to leave one of his assistants behind in order to interact with the location. So, the merchant has to return to this location at a later time in order to pick up his assistant again, and due to the limited number of available assistants careful planning of a player's following turns is needed because otherwise the player might run out of assistants at a crucial moment. This may result in a loss of precious time, or even worse in a competitor taking a good opportunity for some kind of deal. Here it may help to return to the Fountain because all assistants can be called back to that location, but even this action will cost the player a whole turn.

Although the games are totally different, the general feeling provided by Istanbul can be compared in part to the challenge contained in Antoine Bauza's Ghost Stories. Usually the players would love to move to certain locations in order to interact with them, but other factors will cause detours and rescheduling. In case of Ghost Stories such changes were induced by the appearance of the attacking ghosts, whereas in Istanbul it will be the limitation of the assistants and the actions of other players who change the general situation on the gameboard. Locations like the Gemstone Dealer of the Sultan's Palace get more expensive with every Ruby bought by the players, whereas other locations like the markets or the Post Office change their contents after each player interaction. If a player finds his immediate plans spoilt by another player's action, he will need to adjust his following moves in order not to find even more locations changed.

In effect, quite a lot depends on the positioning skills of each player, and even the gameboard layout may offer opportunities to make very effective transactions, sometimes seeing a player move in a circle in order to maximize his gains. Although direct player interaction is rare, especially players who keep an eye on their competitors' development will be rewarded, because a player needs to pay money to his competitor if he wants to interact with a location where this other player is present with his merchant. So, additional money can be made by being at the right location at the right moment, and this effect can be even more devastating if the active player cannot afford to pay this fee. In this case the location is effectively blocked. Another means of interaction is the catching of other players' family members. Each player has one additional member of his family which can be used as a special kind of joker, allowing the player to interact with a freely chosen location. However, the family member will be left at that location, and the first player visiting it now may send the family member to the Police Station and is entitled to receive a reward for this.

The modular nature of the gameboard also helps a lot in keeping the game versatile and interesting, since every new setup will be connected with its own challenges due to the varying distances between the 16 locations. If the distances between corresponding locations are short, the game is much easier to play than with long distances between corresponding locations, because longer distances will demand much more planning and foresight of the players in order not to run out of assistants. In addition, the variable layout also forces the players to reassess their general strategy, because an approach which may have worked in one game may be less effective in another. Due to markings on the location tiles the players can chose between standard setups of varying difficulty, and even more variety is provided by a fully random setup which may bring some rather surprising constellations.

With all these elements falling in place, Rüdiger Dorn has given an impressive example how a traditional theme like commodity trading can be revived and relaunched with a fresh playing mechanism. As I have hinted at the beginning many players will have skipped Istanbul simply by qualifying it is "just another trading game", but the Spiel des Jahres Jury now has shown all these "experts" that superficial estimations rarely are constructive in the world of boardgames. An unexpected gem may be hidden in every new gamebox, and in case of Istanbul it is not just a small trinket but a handful of Rubies!