(x, why?) is "a webcomic of math humour, school life and general geekiness". Expect puns. It was created by Chris Burke, a public school math teacher in New York City, and has been publishing since 2007. He also has a blog running in parallel, where people can leave comments.
Since the comic is "Gag A Day", you can jump in anywhere, but there are some characters who frequently reoccur. These include: Anthropomorphic Numbers (like Kitt 10, or Mr. 0 who hosts a show on F(x) News), Shapes (like Trigonometry Jones), and some Human characters (mostly teachers, like Michael Keegan and Kenneth Wayne). More recent updates occur at random, but strips will also usually appear on significant days of the year, such as Christmas and Veteran's Day.
This webcomic provides examples of:
- All Just a Dream : Averted. The substitute character exists beyond that storyline.
- Another Dimension : References to 3D, as well as 1 and 4 end up in a negative dimension.
- Anthropomorphic Personification : Numbers have identities.
- April Fools' Day : An example here and here (Peebles).
- Beat Panel : Referenced in the notes to this comic.
- Brick Joke : This strip sets up this one which leads to this.
- Exactly What It Says on the Tin : this comic is exactly what it says.
- Guest Strip : Both here (by his son) and here (Peebles).
- I Can See You : The call is coming from inside!
- Incredibly Lame Pun : For instance, pronouncing xkcd out loud.
- Lame Pun Reaction : One incorrigible punster has a coworker girlfriend who is frequently present for his puns. For example, here and here and here.
- Logical Fallacies : Considered numerous times. Here's one for the holidays.
- Mathematician's Answer : Math teachers employ some Coffee Logic.
- Older Than Television : This radio show.
- Police Are Useless : Police generally get the job done, whether the cops are stick figures or even shaped like Keystones.
- Shout-Out : For instance Dinosaurs or the Don't get MAD Dept.
- Show Within a Show : Mr. Wayne sometimes publishes his own webcomic, Ken-Do!.
- Song Parody : Several, including a big one for The 700th Comic.
- Stealth Pun : The order of the jokes in this comic.
- Stick-Figure Comic : Used occasionally. Also Super Stickman was once a Sunday regular.
- Suspiciously Similar Substitute : The substitute teacher, Quinn Jonas. (Funnier when this trope was called 'Jonas Quinn'.)
- Visual Pun : Numerous, for instance here.