Unintentionally funny flyer at the University of Pennsylvania, inadvertently referencing the SARS outbreak of 2003.

Unintentional humor is the act of making other people laugh without actually trying to. There are several different kinds of unintentional humor that arise out of various situations.

Unintended association

The flyer depicted in the picture on the right is an example of unintended association. The author of the flyer only pointed out that it relates to a class on South Asia Regional Studies (SARS), and (independently of that) that its instructor cannot attend because he is ill. Readers are likely to find humor in that SARS is also an illness.

Unintentionally funny combination of "Way In" and "No Entry"

Unintended contradiction

It is possible for unintentional humor to arise when two different well-meaning people contribute independent pieces of information, but in combination, they contradict each other. The image on the left is an example of this.