“Do you trust me? Do you feel I can get you through this night?”
They looked unsure. Slowly, each nodded. One even spoke, “I believe you can get me through this night.”
“Good. I believe we can reach the morning light. Now here is what we need to do…...”
In a city where the justice system features judicial dueling, plaintiffs and defendants are permitted to request a champion to take their place in the duel: Someone chosen by lot from among the foreigners in the city. When anyone first arrives, they are given an enchanted ceramic pendant that marks them as a candidate for "court duty".
Wealthy folk entering the city are often escorted by burly guards, paid to carry pendants on their behalf: They elude court duty in that way.
Adventurers may seek work as a rich man's proxy or may find themselves magically summoned to serve as a champion.