If you do not know the playtester, start by introducing yourself and everyone else in the room. It’s good to put distance between yourself and the product. If possible, pretend that you (and everyone else in the room) are not a part of the development team—We’ve been asked by some people at the company to run this tests for them. This setup allows the candidate to open up without fearing they’ll hurt your feelings.
After introductions, it's important to explain the purpose of the playtesting session and prime the player to vocalize their emotions and intentions. This is essentially a script, which is being run at the start of each session. In fact, you could write and print it ahead, then read it out to each tester. The ...
