What type of whiskey is primarily used in a Dry Rob Roy?

In a Dry Rob Roy, the primary type of whiskey used is Scotch. The Rob Roy cocktail is a variation of the Manhattan, and it is traditionally made with Scotch whisky instead of bourbon or rye. The term "Dry" in this context refers to the use of dry vermouth rather than sweet vermouth, which is found in the classic version of the drink.

Using Scotch provides a unique flavor profile, often attributed to its distinctive smoky, peaty notes, which can enhance the overall experience of the cocktail. Blended whiskey and bourbon, while they may be used in other cocktails, do not have the same authentic connection to the Rob Roy and would not deliver the traditional taste associated with this classic drink. Southern Comfort, being a fruit-flavored liqueur, is not suitable for a Dry Rob Roy as it would alter the intended flavor balance of the drink.