The turquoise worker ability (with the railroad action) states:
Place an additional rail following the usual rules (paying for
any ‘Difficult terrain’ icons).
Does this mean:
a) You place your extra rail for free, plus an additional $100 for each difficult terrain icon.
b) You pay $400 for your rail, plus an additional $100 for each difficult terrain icon.
I'm guessing option a), but am not sure, because of the sentence: "following the usual rules".
I've read all the rules now. Nice game.
Looking forward in playing this one.