Play safe or Dream big?

I am applying for 2019 fall semester and is now trying to decide my ED school, but now I can’t decide it because there are two different opinions around me: one is play safe, choosing a university of my level and ba possibly admitted; the other is dream big, pursuing a school that is slightly beyond my level. Which way should I go?

This depends on a lot of factors:

What is the ED vs RD acceptance rate/state difference for the two schools?
Is the big dream school actually possible or a complete hail mary?
Will both schools be affordable? Does comparing financial aid offers matter to you?

Another factor to consider is how valuable the ED bullet is to you. In other words, if you don’t get any acceptance ED, do you still have colleges you like and that you have a reasonable chance of admission remaining? For example, if you are not admitted to your “dream big” school, are you still likely to be admitted to good options in the RD round?

Assuming everything else has been figured out like @PengsPhils says why can’t you apply to both?

Assuming both are affordable, which do you most want to attend? Have you checked to see if the school at “your level” offers ED2?