Hi I'm a big fan of TDD, thus I have a lot of tests in my current project. Some of those tests are PlayMode Tests, which are executed by the player inside a scene. There are several of those tests, which create an GameObject with the name "MyObject" and start working on that object to test some things. Sometimes the object is deleted an recreated and so on. Now if every test-class in running alone, everything works perfectly. But if I start all my tests with "Run All" many tests which use the GameObject "MyObject" suddenly fail. For example the object is there, while it should not be there. Or the object is missing, when it should be there. I have the feeling, that the PlayMode tests are not well isolated from each other. It seems that every test-class in started in parallel on the same Scene, which would explain those race-conditions. But I was not able to find a detailed description how PlayMode tests are executed. That's why my questions: 1.) Are the PlayMode Test classes executed in parallel? 2.) Are they using all the same temporal scene (also in parallel)? 3.) Is there any way to isolate the tests from each-other? 4.) What happens when any of those tests change the scene? Will the scene be changed also for other tests? In fact I found out, that exactly this is the case, for tests in the same test-class. If any of those tests load a different scene and set it as active, every other test from the same test-class, which is executed later, will working in this scene instead of the temporal scene. But does this also apply for tests of different test-classes, which seems to be executed in parallel?