Actually, in my experience, it CAN happen on a normal/standard attack, without Auto. I actually don't use auto, since Zabuza and his Mist (that I don't always need to use).
I think the only bug is with Haku 2 Star and his barrier, at least, that I know of. This post was last edited by TomatoKat at 2016-9-11 00:32
Ah, whoops, my mistake. After testing a couple times on Kakashi's clones, I've noticed that his Crystal Ice Mirrors can crit, and do acupuncture. It's rare that it happens, unfortunately.
This post was last edited by TomatoKat at 2016-9-11 01:00