The Rushlight Tournament Walkthrough
Soon after completing the fifth chapter, Linzi will bring an invitation from Irovetti, the King of Pitax. So begins the sixth chapter. By the way, if you complete chapter five quests too quickly, the letter will arrive a few weeks later. Head left from the capital and until you reach the Rushlight Fields. It was impossible to go there before, but now you are free to do so.
Go to the location and talk to King Irovetti. If you will try to fight someone in the tournament, the King will chase you away, saying that you are a barbarian with a crown.
Somewhere in the center of the location, you will find a character named Nunzio Arpaia. Talk to him to start the first contest. All the next ones will also be available from him. Each contest will be associated with some skill check, so it should not bring any difficulties. The third contest is a fistfight. Talk to Nunzio again afterwards and ask about the results of the tournament. Do it after completing all the objectives in this location (like talking to the characters needed for Linzi’s quest).