When something bad happens we say "What bad luck!"We do not say "What a bad luck!" because that is not correct in normal English usage.
Good luck with that = viel Glück damit
In the British theatre it is bad luck to say "Macbeth". It is normally replaced by "the Scottish play".
"Glück" is the word you are looking for.
Viel Glück!
"Viel Glück"
Schlecht
The acting profession is very superstitious. True, to say 'good luck' to someone just going on stage is bad luck. Instead acting people say 'break a leg' its code for 'good luck' but the bad spirits don't know that.
"spiderweb in German" ^^ BAD JOKE U
Viel Glück !
warukitsi
my mom and dad say "yes it is bad luck"