Ryan Reynolds' Movie 'IF' Bombs at Box Office, Critics Hating Too

Ryan Reynolds' new movie "IF" must have a lot of imaginary friends in the crowd ... 'cause it's tanking at the box office despite the star-studded cast.

Deadline reports the movie made just $10.3 million on Friday -- including previews -- and, it's headed for just a $30 million opening ... lower than initial estimates projected.

Plus, another negative for the creative new picture ... critics seem to want it to disappear like a kid's IF when they grow up -- it's currently got a shockingly low 49% on Rotten Tomatoes despite its all-star cast.

To be fair, audiences love the flick ... it's got an 84% audience score on RT -- so, fans are happy with the finished product at the very least.

BTW ... Deadline's telling movie industry execs not to panic -- 'cause Paramount took a chance on the film. They say PG-rated live-action films usually don't make a ton, and critics generally don't like them, but they fill a specific niche that usually leads to success long term.

"IF" follows Cal (Reynolds) a man who helps forgotten Imaginary Friends reconnect with the kids who created them after they grow up. The movie stars John Krasinski -- who also directed it -- Steve Carell, Emily Blunt, Awkwafina, Blake Lively, Vince Vaughn, Matt Damon and a whole lot more.

Obviously, with the stellar cast, the movie's gotta make a boatload to recoup its budget which Deadline says is around $110 million.