San Francisco — The CW’s new “Arrow” spinoff, “The Flash,” follows the superhero template to the letter, which could have had the same results as locking Superman in a room made of Kryptonite, but hasn’t.

One reason is the nonthreatening likability of Grant Gustin in the title role of cute nerd Barry Allen, who gets zapped by supercharged lightning when a particle accelerator goes blooey and empowers him with the ability to run as fast as a bullet.

Depending on your point of view and perhaps your age, the show, which premiered Tuesday, is either rather bland or exactly what you’d expect from the CW, which has occasionally tried for a post-tween audience with shows such as “Arrow” and “The 100.”

Like so many superheroes, Barry is an orphan — this time, of the virtual variety. His father is in prison, convicted in the death of Barry’s mother, who in fact died in a kind of whirlwind of lightning inside their home.

The show was developed in part by Greg Berlanti, who also created “Arrow,” and pairs well with it. In fact, Stephen Amell makes a cool cameo appearance in “The Flash” pilot.

But where “The Arrow” is dark, sexual and imbued with a pervasive sense of impending menace, “The Flash” is comparatively lighter fare. The special effects are convincing, and there are well-conceived supervillains, but the show has an overall fluffiness that should hook younger viewers without worrying their parents.