I would say that it does depend on the course and the modules that you are taking. Generally, it is advised to attend the lectures as well as tutorials and seminars that are part of your course. And generally, for tutorials and seminars, attendance is taken. Though attendance is not taken for the lectures but it is recommended to attend them nevertheless.
Speaking from personal experience, I am languages student, and if you are studying a language as part of your course, it is not a good idea to skip a language class as you will have difficulties following up with the subsequent sessions.
There also certain visa requirements for you to attend your classes, if you are an international student.
Hope this helps!
-A (MA Iranian Studies and Persian)