A
logical fallacy in which it is
assumed that because
one thing happened after another, the first
caused the second. Also known as
post hoc ergo propter hoc. The problem here is that
correlation does not equal causation.
Example: "I walked under a ladder, and two minutes later a meteorite hit my car! So walking under a ladder is bad luck!"
To prove the fallacy, show that the correlation is coincidental. Showing that either the effect would have occurred even without the cause or the effect was caused by something else is a good way to go about this.
If it were "I walked under a ladder and got
hit in the head by a paint can", the walking under the ladder may
in fact have caused the
paint can to fall on your head. But it's still
not bad luck.