Single Player: End an enemy's career as a CELL operative by wounding him in the knee with an arrow! [Bronze / 20G]
You will automatically get the Predator Bow in mission 1. Hold down the select-button and set the draw weight to "low". Choose the Carbon Arrows. This will ensure that you do the least possible damage per shot. Now look for a human enemy and shoot their knee. Tap R1 (PS3) / RT (X360) for just a short moment. If you hold down the button for too long you might kill the Cell Operative in one shot. The Cell Operative has to survive this incident.