You can now include a question in a test without it counting towards the score. Open the options menu (⋯) on any question and choose "Exclude from grading" — either in the editor or straight from the results view.
Excluded questions are still shown to students, answered, and graded as usual. They simply don't count towards the total points or the final grade, and the totals and grades recalculate automatically around them. They're marked with a "Not graded" label so it's clear at a glance.
This is handy for reflection or survey questions, warm-up questions, or trying out a new question without affecting anyone's grade. You can also drop a flawed question after the fact, without deleting it or losing the answers students already gave.