Knee Shot
Source
Armory pg. 150
For your debilitating trick, you can attempt to knock the target prone. The target must succeed at a Reflex save or fall prone. If the target gains a bonus to its KAC against trip combat maneuvers, it adds this bonus to its saving throw, and if it is immune to the trip combat maneuver it is immune to this operative exploit. Once you’ve used this ability to attempt to knock a target prone, that creature is immune to your knee shot for 24 hours. This exploit counts as staggering shot for the purpose of meeting the prerequisites of other operative exploits.
Dragonscript
ID
66d3b732ad3b2ef7e41f163b