At the risk of nerfing myself...

Just like Reveille never worked, it seems Nocturne of Fright always works. I don't think I've ever seen it fail in a fight against another player. As a comedic bard I expect causing fear to be something I'm not very good at (the helpfile says as much), but it's so reliable in a fight I'm beginning to feel guilty about using it.

Even against people with enough protections that I can try, and fail, to distrort or put to sleep multiple times, I can land nocturne of fright every time.

I believe the only time I've ever seen it fail are times when the anti-gang code has distracted them from hearing it in the first place.