Hitman 3 Certainty Principle is a mission in the game's Chongqing location. Your target for Certainty Principle is the ICA scientist Imogen Royce. Here's how to sneak into to the lab to take her out and how to hit those assassination challenges along the way.
Hitman 3 Certainty Principle: How to Complete
You'll start in a dumpling restaurant where Mr. Pritchard and Royce's assistant are having a meeting. Go into the kitchen and disguise yourself as a chef. Go to the bathroom to find some rat poison, and add it to Pritchard's food. Ring the bell to get the server.
Pritchard will run to the bathroom, where you can take his clothes. Go across the street to the apartment building and break into Pritchard's apartment with code 0-1-1-8. Go to his bed and find the P41 Form you'll need. Head back to the restaurant, and Royce's assistant will take you on a tour of the facility.
As you go through the tour, be sure to grab the dongles so you can hack panels later on.
If you want to complete some assassination challenges, be sure to save as soon as you meet Royce. The first challenge starts right when you meet her, and you can throw her off the railing. Do this and reload your save so you can get the next challenges.
When you're in her office, you'll get to fire some of her employees. To complete Human Error, fire Reynolds as soon as Royce asks. Then, fire Bolt, who will distract Royce's bodyguard. When Reynolds goes to leave the core and Royce is about to enter it, fire Sharon Reed who will, in turn, incinerate Royce.
A Shock to the System and Venting Some Stress needs you to bring Royce to the break room. You need the tier 2 dongle from earlier. Hack the computer in the Analysis Area so the analysts get scolded in the break room. Tint the windows by hacking, and then puncture the water machine when Royce goes near it for A Shock to the System.
For Venting Some Stress, you'll need the poison vial from hitting rank 10 in the Berlin level. Go to the nearby maintenance room while Royce is in the break room and poison the ventilation system.
Either way you choose to deal with her, you can loot the tier 3 dongle to wipe the core's database for the story mission.