Risk

The most well known game on 4chan, with origins reaching back to 2010 and maybe even before then.

Gameplay
The basics involve using the last digit of the post number to "roll" and fill territories on a map. The maps can be of real world geography or fictional settings. The game can also be played on discord or another similar app by using a bot to "roll" a randomised number and use it in place of a post number.

History
"Without any doubt risk exists from at least 2011. A decently high enough number of people claim it to exist since 2010, and some oldfags even claim it started around 2008." Swiss Dave, The Circle

"An archaic form of risk existed all the way back to 2006. Back then we just colored in squares and tried to form tribes from our squares." - Anthony da Cat, from The Circle

"I miss Mado, bring back the autocracy." - Ash, an Oldfag

Risk also once had an active forum which served as a hub for mapmaking and general risk discussion, but since the advent of discord and replacement of skype, the forum is practically unused.

Current Boards

 * 4chan - /int/, /pol/, /b/, /tg/, /mlp/,
 * 8chan - /risk/,
 * Other Sites - unknown

Communities
The Circle Risk was one of the largest single Risk communities in recent times and more than likely the largest single unified body to exist at any given time. It has since been fragmented over and over during what became to be known as the "Autism Wars" of 2015-2018, and their subsequent skirmishes from 2018 onwards. From TCR, many factions and groups emerged and evolved over time, such as Monocrotis and his shitposters or Freddit and his SPQR.

Risk has also spawned multiple sub-communities based around varying versions of the game itself, rather than the larger community. Most notable of these is /GoB/ or "Game of Bros".