I made this simple project a while ago to test the subtleties of Scratch's scheduling for broadcast receiver scripts (within a single sprite) when some of the scripts are already running. I decided to share it since it might be useful in the Studio for Scratch 3.0 testing: https://scratch.mit.edu/studios/3424369/ Hit space to send the broadcast that starts the three scripts. The first time you hit space, the order that the scripts get started will be FIRST, SECOND, THIRD, and all of them will be started straight away (i.e. near zero time). The 2nd and 3rd times you hit space will give different run orders, and different startup times, because some of the scripts were still running when the broadcast was resent. See info text below list, and see inside for more explanation.