To accept or defer?

Hi all,

If a prospective student applies to multiple schools, and they are accepted to one while waiting to hear back from their top choice, can the student accept a spot, pay only the deposit, and still be able to change their mind if their top choice offers them a seat?

I understand a tuition deposit is non-refundable, that's fine. But, if you accept a spot at your second choice and pay the deposit, can you change your mind if you are accepted to your top desired program about a month later? Both of these possible programs don't start for a minimum of 6-8 months from now if that matters.

Thanks for any info! :)