The Treaty

Our archaeologists have learned that after a long and bitter war, the two empires inhabiting this corner of the galaxy some 200,000 years ago signed a treaty compelling them to settle all future disputes with arranged and highly regulated combat engagements between robotic armies. … was chosen as the site of these battles. The treaty appears to have been upheld for nearly two centuries, preventing the outbreak of armed hostilities on numerous occasions, until one of the empires was caught cheating.

The command below will trigger the "The Treaty" event in Stellaris:

When this event fires, you can choose between the following option:

• Curious.
  • Engineering: +None to None