In working with teachers in professional development I have been asked this question. Here is a strategy for allowing students to use a rubric for self-assessment:
Rubrics are an item that is graded within Moodle. Students do not have permission to grade so they will not be able to use a rubric by clicking on criteria and adding comments. However, there is a way to work around this if you have an activity where you would like students to self-reflect on a rubric.
Assign students to the Non-editing teacher role for a specific activity. The role of Non-editing teacher allows grading but not editing of the course. When assigning students to this role within an activity, they can only grade within that activity.
Let's say you want students to use a rubric as a self-assessment tool for a project. Create an assignment in Moodle and add the rubric. Assign students the role of non-editing teacher in this assignment only.
There is a potential drawback to consider. Students will be able to see and "grade" the rubric of all other students. However, you will know if a student has graded the rubric of another student. The profile picture and name of the last grading teacher or non-editing teacher always displays with the graded rubric.