The Contract Conspiracy ...
Thinking that the discussion could use some good legal advice, I wrote to both Jonathan's less good looking brother, Glenn, and to Eugene Volokh of The Volokh Conspiracy. Both of them are very busy and smart professors of law, so I was fortunate to get an answer from Volokh. With his permission and his caveat that this is his"quick-and-dirty" take on the issue, here is his answer:
the short answer is that the syllabus almost certainly isn't a contract, because it wouldn't be understood as intending to create a binding promise -- only a general plan that it's understood the instructor can deviate from. Simple analogy: Say that you promise an article for a symposium, and you say you'll say X. Then you realize that X isn't quite right, so you instead say X'. Now the symposium editor might be within his legal rights to refuse your submission; but he surely can't sue you for breaching your contract to write something that says X. And that's because your statement, even if it's in writing and in some detail, is an expression of your plan, not your promise.How that might affect an attendance policy, Volokh does not say. Presumably, however, the syllabus itself and whatever it in particular might say about attendance, would not be considered to have the binding effect of a contract.