Ticket to Ride: Heart of Africa is the first expansion to really change the basic game significantly. It does so in two very distinct but related ways. It adds a third deck of terrain cards, giving players a choice of drawing train cards or terrain cards each turn.
But the bigger change is to the board. In all other versions of the game, you try to not have any city connect by more than one route of any color (except grey). But in this game, you want the cities to have as many routes of the same color into them as possible. This changes the way players must draw cards, and adds quite a bit of value to the wild cards, with the gold at the end of the rainbow being the extra points players score for the terrain cards.
