* The school's policy: Each school, and sometimes even individual teachers within a school, sets its own attendance policy. Some might have a strict minimum percentage of days attended, while others might be more lenient.
* The course: Some courses might have more flexible attendance requirements than others. A lab science course, for example, might have stricter attendance requirements than a lecture-based history course.
* The grading system: Attendance might be factored into the final grade, or it might be a completely separate requirement. Failing to meet the minimum attendance requirement could result in failing the course, even if your test scores are high.
To know the specific attendance requirements for a course, you must check your school's student handbook, course syllabus, or contact your teacher or school administrator.