2AlexSpl: To get in there, you need to direct the movement through the castle gates and, while flying over them, press SPACE! It works, I've checked!
Added 5 minutes later
By the way, thanks to this mini-investigation, I finally saw the failure animation (a thundercloud and lightning) :)
In Heroes III, there is no such thing as "anti-luck." And as for what was written here about the uselessness of the devils' ability and the "bad luck" spell, it depends on how you look at it. If the opponent has +1 to luck, devils will be useful; with more luck, "bad luck" will work on everyone.
