You've finally had enough with all of the nobility, and it's time to rise against them and reclaim the fortress to its rightful rulers!
In Riot mode, your objective is to capture all of the nobility as well as the inner-circle protecting it. You spawn as a riot leader, with options to recruit people to your cause through the riot tab. However, be careful, as one false move will land you into the dungeon to spend the rest of your days being tortured, raped, beaten, and all around generally having a bad time.
Help is scarce, and there is usually only two or less riot leaders that actually spawn at the start of the game. Most commoners have equal chance of becoming a rioter, while others like the nobility are immune. Keep in mind though, that doesn't mean the nobles are staging a coup against the baron for their own benefit!