In the 2nd mission of Black Riders are some cards which offers the player a simple choice between to things. A good example is Bill Ferny.

The card reads: "... either shuffle 1 out of play Ringwraith into the encounter deck or each player raises his threat by 1...". Does this mean that
a) if there are no Ringwraiths left I am forced to chose the other option
or
b) I can chose that Ringwraith option, but then -because of there are no Ringwraiths left- nothing actually happens?

I've possible found a passage in that official FAQ, but as a not native speaker its hard to understand. I guess its a) then?

The term "either ... or" means you can choose one or the other, but you cannot choose something that is impossible, so a)

Hello, I have another question regarding this card (Bill Ferny).

If I don't commit heroes to the quest, can I choose the second option and increase my threat by 0 (supposing that the number of hero committed is 0) ?

I know the faq point 1.44, but the second option of this card should be considered as soddisfied, if I consider the number of committed heroes as zero?

Thanks

Yeah, committing zero and then picking the second option is all good, since each can include 0 like you said.