Most campuses call this "challenging" - I did it several times. In city college, I successfully took courses without their prerequisites by speaking with the pr

Most campuses call this "challenging" - I did it several times. In city college, I successfully took courses without their prerequisites by speaking with the professors and showing them my work/experience. It wasn't test-based, just portfolio review. In university, successfully challenging also gives you credits for that course (though there is a small fee per unit). I successfully challenged four courses (all in graphic design) - three of which were based on portfolio review and the fourth was based on completion of course projects in an accelerated period. Additionally, though not quite a challenge, I was able to speak with a couple CS professors and get them into admitting me into their courses despite not having the prerequisites (though was doing them concurrently). The course requisite structure is more a guideline than a rigid computer system that works one way and only that way.