The main criteria for a dress watch comes in its thickness. The idea here is that dress watches should be relatively thin so it can slip under the cuff of a dress shirt. Because of this, dress watches are by and large uncomplicated, offering a simple yet elegant dial design along with a standard 3-hand function.
Highly respected brands have also been known to offer exceedingly complicated complications such as minute repeaters, perpetual calendars and gyrotourbillons as dress watches simply because they have the know-how to keep this watches relatively thin, and also have a high level of finishing.
There was a time where the best dress watches were usually made from precious metals such as gold or platinum but these days there are steel watches that share the same prestige because of its rarity.