body: In many different situations, people will have an incentive to lie in court while the other parties cannot verify whether they are lying or not. 
  
  
  I'm wondering whether there are techniques that can be used to (relatively robustly) incentivize people not to lie, even though what they say cannot be verified/falsified. 
  
  
  For example, one technique that might be used is:
  - We will ask you 10 questions. We know the answer to 5 of these questions, but you don't know which of the 10. If you tell us a lie in even one of the 5 cases, you will go to jail. 
  
  
  That person will be incentivized to tell the truth in almost all 10 cases, since statistically, if it lied in half of them they would almost certainly go to jail. In this way, we incentivize the person to tell the truth even in the cases where we can't verify the answers.
  
  
  **Are there methods that are used to achieve this?**
  
  
  
title: What are techniques used in law to robustly incentivize people to tell the truth?