In Istanbul, you lead a group of one merchant and four assistants through 16 locations in the bazaar. At each such location, you can carry out a specific action. The challenge, though, is that to take an action, you must move your merchant and an assistant there, then leave the assistant behind (to handle all the details while you focus on larger matters). If you want to use that assistant again later, your merchant must return to that location to pick him up. Thus, you must plan ahead carefully to avoid being left with no assistants and thus unable to do anything...

In more detail, on a turn you move your merchant and his retinue of assistants one or two steps through the bazaar, either leave an assistant at that location or collect an assistant left earlier, then perform the action. If you meet other merchants or certain individuals at the location, you might be able to take a small extra action. Possible actions include:

Paying to increase your wheelbarrow capacity, which starts the game with a capacity of only two for each good.
Filling your wheelbarrow with a specified good to its limit.
Acquiring a special ability, and the earlier you come, the easier they are to collect.
Buying rubies or trading goods for rubies.
Selling special combinations of goods to make the money you need to do everything else.
When a merchant has collected five rubies in his wheelbarrow, players complete that round, then the game ends. If this player is the only one who's reached this goal, he wins immediately; otherwise ties are broken by money in hand.