How to investigate (and get control over) the execution order of 3 Rules working on the same action? I have three Rules to do something after saving content. I need to know which one is executed first and how I can control this order?

Is there a certain answer for this question?
It's based on the weight. Edit the  Rule settings and you'll find a drop down to set the weight. I believe those with a lighter weight, e.g. -1, are  executed before those with heavier weight, e.g. 5.