GreedFall Dangerous Bets Walkthrough
This mission will begin after some time (after several storyline quests). Talk to Petrus and agree to help him. Head to San Matheus bookmaker and arrange a fight. Then, visit Candy Cane at night and convince him to make a bet against you. Give him 250 coins as all other options will lead to a fight and to a loss of reputation with the Coin Guard. Wait until the beginning of the fight, rewinding time 24 hours ahead, go to the arena and defeat the champion in a one-on-one battle. Return to Cornelia and talk to her to complete the quest.
Reward: 1300 experience points, +3 to reputation with Petrus.