Wonder Jacob Tremblay, Julia Roberts, Owen Wilson. Directed by Stephen Chbosky. Rated PG. Opens Friday citywide.

There’s been a whole lot of wonder at the movies this year: Wonder Woman, Professor Marston and the Wonder Women, Wonderstruck, Woody Allen’s forthcoming Wonder Wheel. And now here comes just plain Wonder, adapted from R.J. Palacio’s 2012 children’s book about a 10-year-old boy born with mandibulofacial dysostosis, a genetic disorder that makes his face look like that of a severe burn victim who has undergone reconstructive surgery. Auggie, played in the movie by Room’s Jacob Tremblay, is a smart, sensitive kid whose loving parents (Julia Roberts and Owen Wilson) have home-schooled him until now. But it’s time for him to join the wider world, even if that means dealing with childhood cruelty.

Directed by Stephen Chbosky (The Perks of Being a Wallflower), Wonder deftly avoids many of the mawkish pitfalls endemic to this sort of inspirational story. Characters are neither one-dimensionally virtuous nor villainous, and the film expands to consider, for example, the frustrations of Auggie’s older sister, Via (Izabela Vidovic), who understands why she’s not the center of attention in her family and feels guilty about resenting that anyway. But the movie also engineers an improbable feel-good ending for just about every character, and the narrative tidiness undermines the preceding complexity. Wonder falls somewhere in between a genuine drama and an earnest anti-bullying PSA. It’s just good enough to make you wish that it were a whole lot better.