The subject matter of the comic varies from statements on life and love to mathematical, programming, and scientific in-jokes.

It has a cast of stick figures,[3][4] and the comic occasionally features landscapes, graphs, charts, and intricate mathematical patterns such as fractals.

is based on his blog of the same name that answers unusual science questions from readers in a light-hearted way that is scientifically grounded.

As a student, Munroe often drew charts, maps, and "stick figure battles" in the margins of his school notebooks, besides solving mathematical problems unrelated to his classes.

By the time he graduated from college, Munroe's "piles of notebooks" became too large and he started scanning the images.

[13] xkcd began in September 2005, when Munroe decided to scan his doodles and put them on his personal website.

According to Munroe, the comic's name has no particular significance and is simply a four-letter word without a phonetic pronunciation, something he describes as "a treasured and carefully guarded point in the space of four-character strings".

The story began with a male and female character building a sandcastle complex on a beach who then embark on an adventure to learn the secrets of the sea.

Around 2007, Munroe drew all the comics on paper, then scanned and processed them on a tablet computer (a Fujitsu Lifebook).

[21] Munroe has been a fan of newspaper comic strips since childhood, describing xkcd as an "heir" to Charles M. Schulz's Peanuts.

Munroe cited the lack of a need for editorial control due to the low bar of access to the Internet as "a salvation".

[2] xkcd frequently features jokes related to popular culture, such as Guitar Hero,[23] Facebook,[24] Vanilla Ice,[25] Linux,[26] and Wikipedia.

[27] There are many strips opening with the words "My Hobby:", usually depicting the nondescript narrator character describing some type of humorous or quirky behavior.

[22] Romance and relationships are frequent themes, and other xkcd strips consist of complex depictions of landscapes.

[‡ 13]Nearly all xkcd strips have a tooltip, the text of which usually contains a secondary punchline or annotation related to that day's comic.

He gained a girlfriend, commonly named "Danish" by the community, during the course of a small series called "Journal", who is just as cruel as he is.

He also has magical abilities,[33] which often manifest in the creation of situations or objects that support his overly optimistic worldview, even when in direct violation of societal norms or the laws of physics; an example is his startup making incredible amounts of money despite his not even knowing what it does.

[‡ 18] Geographical maps, including their various different formats and creation methods, are a frequently recurring theme in the comic.

[36] On several occasions, fans have been motivated by Munroe's comics to carry out the subject of a particular drawing or sketch offline.

[22] Some notable examples include: In addition, a number of researchers have acknowledged particular xkcd comics as the source of inspiration for their scientific articles.

[79] The book tour in New York City and Silicon Valley was a fundraiser for Room to Read that raised $32,000 to build a school in Salavan Province, Laos.

[‡ 6] On February 5, 2019, Munroe announced a fourth book, titled How To, which uses math and science to find the worst possible solutions to everyday problems.