I've had a look through the FAQ and either I'm going blind or there's no mention of how much rep an acceptance earns. On SF it's 15, so I naturally expected the same on MSO. However, when I logged in today, which I do infrequently, I was somewhat astonished to learn I'd reached the daily cap and the mortarboard badge with this answer that received only 2 up votes and an acceptance. Surely that can't be correct?
The tooltip on the accept arrow will tell you what's going on.
Also, if the accept arrow is "glowing" that's a bounty accept.