Oh Really, when you submit the Common App, you check a box before signing that agrees you will not double deposit. The only time it is acceptable is if you get off a waitlist after May 1 — then you deposit at the new school and immediately notify the old school that you aren’t coming after all. It is dishonest to do otherwise.
If you are caught, you may lose both acceptances. GCs have to provide final transcripts, too — and if the GC finds out they will be very unhappy because your bad behavior reflects on your whole HS, and could affect future applicants.
You may think it is cool to “play”’schools. I assure you it is not. And playing fast and loose with your word (as you gave when you signed the Common App) shows poor character and will come back to bite you.