Each finding has 1 to 8 points for how specific it is. Some combinations are worth more than their parts (Charcot's triad, fever with a new murmur); when a line contains a named combination it earns that bonus and the score names it. A diagnosis is a word with a grammar: a valid line has 3 to 6 findings that the disease lists, at least one of them a core finding (the white dot on the tile marks findings that are core for some disease) and at least one more that is core or characteristic of the disease, nothing that rules it out, and points adding up to 12 or more. A finding earns its full points only where it is core; findings that are characteristic of the disease though common elsewhere (its key findings) earn 2 extra there; another disease's signature counts at most 2 and cannot be one of the three findings that make the line. Findings from the same cascade (dilated duct, direct bilirubin, jaundice) count in full only once; the rest count half. Normal or negative findings (CT head normal, ANA negative) are pertinent negatives: they fit the diseases that list them, where a normal result is part of the picture, and rule out the diseases that depend on the abnormal one. Light blue and dark blue squares double or triple a finding; pink and red squares double or triple the diagnosis. Placing 5 or more tiles in one turn adds 15. A disease you have not made yet adds 10, and 5 more if it is a distinctive one (most of its findings belong to it alone); making the same disease again scores half. Lines can be extended later, and a tile can sit on two lines at once.
After the first turn, every new line must run through a tile already on the board, so that shared finding has to fit both diagnoses. If your tiles also complete a sideways line of 3 or more, that line is checked and scored too. Two tiles touching sideways are ignored. Ten hints per game; each shows one diagnosis your rack can make.