Tom Berenger stars as Shale, a professional mercenary suddenly out of a job. When he returns home to his girlfriend Jane (Diane Venora), a teacher, he's in time to witness her getting her legs broken by a thug who represents a gang. So Shale sets himself up as "Smith", the substitute teacher for Janes' class. He therefore divides his time between trying to pass himself off as a teacher, and combatting the schools' overwhelming drug problem.
As others have said, this movie was never meant to come off as "high art". It's just straightforward action entertainment. And it serves its purpose well, offering plenty of violence - gunshots, explosions, etc. The protagonists are generally worth rooting for, and the villains are all despicable scum who can't die soon enough. Yes, this is very much formula filmmaking, but it works, thanks to efficient direction by Robert Mandel, decent action sequences, and a pretty good cast for this kind of exploitation fodder.
Berenger is engaging in the lead, receiving strong support from the appealing and under-rated Venora, and Ernie Hudson, the latter cast as the principal of the school. Raymond Cruz, Luis Guzman, Richard Brooks, and William Forsythe play the various members of Shales' team of mercs, and singer Marc Anthony and Rodney A. Grant are among the assorted bad guys. Glenn Plummer plays a teacher, Shar-Ron Corley and Maria Celedonio two of the students in Janes' class. Cliff De Young (with whom Mandel previously worked on "Independence Day" (1983) and "F/X") has one of his typically weaselly roles as a lawyer whose farts are a running gag.
All in all, good fun. The writers (Roy Frumkes, Rocco Simonelli, and Alan Ormsby) know that you don't have to reinvent the wheel to show an audience a good time, and "The Substitute" entertains sufficiently even as it runs close to two hours long. It does have a sense of humour, which helps: the scene where Shale throws punk after punk out a second story window is priceless.
Followed by three direct-to-home-video sequels, each starring Treat Williams.
Seven out of 10.
