What's the minimum you need to pass a course and have it count as a pre-requisite (ie: not having to retake it ever again)?

A 1...50%, which is a "D-"

http://registrar.mcmaster.ca /calen...-13/pg145.html

Pre-requisites are treated as any other courses unless it says otherwise. As long as you pass, it should count except in the odd case where it explicitly says you need to achieve a certain grade to take a course

Yes double check to make sure there isn't anything saying you need a high grade (usually a 60%) to pass. |I know that in my core nursing courses we needed to have a 60% to pass the course.