The Portuguese King has called the finest stonemasons of the country to pave one of the most important squares with calçada tiles (worldwide famous black and white tiles that pave several squares in Portugal). But the task is enormous and players will have to count with the aid of helper cards who will help them score points and/or collect money.
Rossio is all about timing: Recruit a card face-up late in the game, and then it will score fewer times than expected. Recruit it too early, and it will score you a few points since there are few tiles built on the square. To many cards recruited face down will give that extra amount of money, but, they won't score any points. Build several tiles and you're probably helping your opponents. Build fewer tiles and you probably won't have money next turn to recruit a face-up card.
