Good question! The number in the study score (raw SS) doesn’t tell you whether you passed or failed. The SS is your ranking against the state for that U3/4 subject. (And if I remember correctly, you won’t get a study score if you fail both U3&4 in any non-English subject, or either U3 or U4 of your English subject.) If you really want to learn how VCAA calculate SSs, see this post from the archives.
It’s actually the overall S or N status from VCAA that determines whether you passed or failed that unit (for all units, including U1/2), but be careful, as failing certain and/or too many units could mean that you won’t receive your VCE certificate. There was a similar question in the archives about failing units here with a great response. VCAA also list their requirements to pass VCE here.
However, warning: if, like in your example, you receive a raw 20 SS for English, and you’re absolutely deadset on a course with a prerequisite of a raw 25 SS for English (as an example), then you will significantly lower your chances to get into that course (read: near zero), even with a high ATAR above the selection rank. So always aim to do better than the prerequisite where you can, to avoid this scenario altogether.
Hope that answers the question.
tl;dr: Overall S or N from VCAA determines pass/ fail. SS themselves are not pass/ fail, but lower SSs can impact your chances at certain course pathways, especially if it’s for a prerequisite.
