Mr. Moto's Gamble is a decent but different entry in the Mr. Moto series. The anomaly is explained by the film's convoluted history. It began as an entry in the Charlie Chan series, to be called Charlie Chan At the Ringside, but a contentious relationship between the studio and star Warner Oland ground production to a halt. Rather than throw away all the preproduction work and a couple days' shooting, the script was hastily rewritten as a Mr. Moto film. A few lines of dialogue explain the presence of Charlie Chan's number 1 son (Keye Luke), and the result is a fun crossover episode that fans should appreciate.

The film functions fine as a Mr. Moto film, and the character is handled well enough, perhaps because Moto is defined more by Peter Lorre's incomparable performance than by the writing, but it's easy to see how swapping out Moto for Chan would make a more seamless fit. And it illustrates just how different the two characters and the two series are. Nonetheless, a good mystery is a good mystery, and despite overlong asides with the comic relief characters, this one fits the bill.