Never having seen the play, I can’t say for certain if they’re hijinks are faithful to the original material, but I’d guess that they are. However, one part of adapting material from another medium to film is removing or changing the things that don’t work on screen. The antics of Shapiro and “Animal” should have been cut or sharply curtailed. Unfortunately, I think producer/director Billy Wilder probably felt some obligation to carry over Strauss and Lembeck from the original Broadway production of the play.
The central story, about a barracks at German stalag struggling with the specter of an informer in their midst, is first-rate and the silly burlesque is only a too-frequent and annoying distraction. The chief suspect is Sgt. J. J. Sefton (William Holden) , an amoral loner who openly barters with the Germans for privileges and luxury items. When the planned escape of two prisoners ends in them being killed, suspicion immediately turns to Sefton, who callously bet against their success. When they find out the German commandant, von Scherbach (Otto Preminger), knows about the tunnel, the existence of an informer is a virtual certainty. Other signs of German omniscience eventually push the POWs to the breaking point and lead to a violent confrontation with Sefton. Realizing that his life depends on exposing the real informer, Sefton starts trying desperately to learn his identity.
Even more than The Great Escape, Stalag 17 is the obvious inspiration for the TV series Hogan’s Heroes, even down to the prisoner’s convivially antagonistic relationship to character named Sgt. Schulz (Sig Ruman). The similarities were close enough for producers of this film to successfully sue the makers of the series. Unlike the Nazi buffoons in the TV sitcom, however, the Germans here have the competence required to represent a genuine threat. Behind Sgt. Schulz’s outward bonhomie, there is real calculation and threat as he acts as a messenger between the informer and the commandant.
Had the unnecessary comedic elements just been toned down, Stalag 17 would have been a near perfect movie. As it is, it’s still good enough to justify its classic status, with qualifications.