I have a similar question where I haven't found a solution yet:
I would like to have an upper limit of points for a quiz: E.g. there are three multiple answer questions in the quiz, each of them worth one point, but students can get only 2 points in total for the entire quiz. So if they would get 2.5 points, this is cut off at 2 points. (And it should be cut off, not recalculated based on the overall percentage.)
Even better would it be if this worked across several quizzes. E.g. there are 5 quizzes in an assignment group, each worth 1 point, but overall students can get only 3 points for all the quizzes in the assignment group.
If they aswer all 5 quizzes correctly, their points are cut off at 3. If the answer 4 quizzes correctly, their points are still cut off at 3. if they do only 3 quizzes and get 2 points, these 2 points will count.
And the points earned are shown in the gradebook automatically, without the instructor having to adjust points manually (there are too many students to do that).
This way students would have options, they could choose if they want to do all the quizzes, or if they miss sone they can still get the maximum point number, and so on.