In light of this thread, I thought it might be fun to share stories -- not of legitimate embarrassing moments, but ones caused by Doin' It Wrong (messing up rules, forgetting things, etc). Just so, you know, everyone knows we all fuck up *lol*
Off the top of my head:
As an ST, I should know the rules. I like being a rules lawyer. However...
Protean
For almost four years, we played with Protean's Aspect of the Predator projecting an elevated BP. Until Whisper said something. It was explained to me as working one way, I never questioned it, and so we did it wrong for a REALLY LONG TIME. oops.
Predator's Taint
Similarly, we used to use Predator's Taint like vampire radar -- that you could feel it. Core says you have to become aware of the person before it hits. You can't track someone in a crowd, or feel them enter a room. oops.
Character Creation
When I made my first vampire, I didn't read the book. At all. I'd just been building Vampires as Antagonists for my mage game, so I just read the powers. My initial character submission? I picked a VII Bloodline (Akhud). oops.
I'm sure there's a ton more, but those are my three biggest facepalms that come to mind to kick this off