Oh boy, oh boy, where do I even start? xD
I was playing an alcoholic, she got wasted before a big fight. Series of dumb, drunk choices lead to completely altered next act - as our DM told us after the campaign. He had very different plans and he REALLY did not expect things might go sideways so hard.
Different one, we had to break into a house, it was supposed to be a simple thing. Throughout the whole evening I think no one rolled higher than 10. Maybe I'm exaggerating a bit, but it was overall such insane disaster, it was like if 5 Wil Wheatons were playing.
If you know about 'Wil Wheaton's curse', you know how bad it was ;)