Accepting and then rejecting PhD offer

[steve1]

Hi, I was just wondering out of interest, if I receive a PhD offer, accept it and then receive a better offer, am I allowed to withdraw my acceptance (as long as it's before April 15)? Is accepting the offer legally binding?

[incoherent.sheaf]

Just don't accept before April 15th, unless a program makes you (which I don't see any US program ever doing). But no, I am pretty sure you aren't legally required to do a PhD just because you accepted an offer. It isn't like applying Early Decision in undergrad, where you are legally required to not apply to any other schools. But in any case, accepting an offer before the 15th while waiting to hear from programs you prefer is a nonsensical idea.