Wheaton's Law is an internet axiom which states "Don't be a dick." It was originally used in the context of sportsmanship in online gaming but its scope was eventually expanded to apply to life in general.
The axiom was coined by American actor and writer Richard William Wheaton III (Star Trek: TNG) during his keynote speech at the Penny Arcade Expo (PAX) in August 2007. One of the core messages of Wheaton's speech was the importance of sportsmanship in online gaming, which eventually became encapsulated in the phrase "Don't be a dick." While the actor's PAX speech is attributed as the original iteration of the law, the colloquial phrase "Don't be a dick" had been in widespread use prior to the event, since as early as 1999.
The keynote speech and his proposition were met by positive reception from the audience and the webcast viewers at home, as well as significant coverage from a number of well-known geek culture blogs like Ars Technica, 1UP, and Joystiq. The axiom was once again highlighted in Wheaton's blog post about his PAX experience published on August 22nd:
One of the core messages of my speech was "don't be a dick" when you play games online, and a lot of people told me how glad they were to hear that. I think I may just go ahead and make it my new motto:Wil Says, "Don't be a dick!"
. . . or something. I'm working on it.
Soon, both the statement "Don't be a dick" and its eponym "Wheaton's Law" became adapted by various blogs and news sites specializing in video games, internet humor, and geek culture, further boosting its notability. On February 9th, 2009, the single serving site RuleOfTheInternet.com was launched with a single-line text message that simply read "DON'T BE A DICK".
On November 22nd, 2009, comic illustrator and writer Bill Willingham tweeted a revision of the law which established an exceptional clause for those playing characters on television:
@wilw Bill's revised standard version of Wheaton's Law: Don't be a dick, but it's okay to play one on TV.— Bill Willingham ( @BillWillingham) November 23, 2009
The official Facebook page for Wheaton's Law was created on December 1st, 2009 and it has since gained more than 1,000 likes (as of June 2012). Later that same month, the first Urban Dictionary definition for "Wheaton's Rule" was submitted on December 31st and another definition for "Wheaton's Law" was submitted on June 7th, 2010. Through the late 2000s, the number of page results matching the search term "Wheaton's Law" jumped from 96 results in 2008 to more than 2,250 results by 2011, while the volume of page results matching the key phrase "Don't be a dick" saw a similar but more moderate increase of 6,060 results in 2008 to 41,300 results by 2011.
On April 28th, 2011, YouTuber 8O8X posted a stick figure animation titled "it's okay to not like things," accompanied by an innocent tune that goes "don't be a dick about the things you don't like."
In February 2012, Wired Magazine's Geek Mom columnist Nicole Wakelin wrote about her challenging experience of having to explain the axiom and Wil Wheaton to the fellow parents of her daughter's classmates. The article was linked in a thread on FARK a few days later.
 Penny Arcade Forum – Remember that guy who didn't follow Wheaton's Law?
 AimClear Blog – Wikipedia @ SMX: Don’t be a Dick Or It’s Shoot On Site