With pegasi red and unicorns blue,
They're all cool horses - purple alicorns too!

Some tropes can be pretty broad. Some can be so broad that even a specific form of them can be tropes by themselves.

Let's say there's a trope for "Juggling". You realize that "Scarf Juggling" and "Knife Juggling" are pretty common as well, to the point where you can think of half a dozen examples for both. Those would be Sub-Tropes, whereas "Juggling" in general is their Super Trope. In logic terms, "Juggling" is the genus and the different kinds of juggling are the differentia; they share the same common theme in their definition, but they each have additional features that distinguish one from another.

What makes a sub-trope can vary. Perhaps the most common way is that several examples of a trope have a common element not seen in the other examples. That makes them distinct from the larger trope while still being included. Or, as mentioned above, a trope can have several possible variations built in, and once examples of any of those variations are common enough, they form a sub-trope. These sub-tropes can be listed instead of the super trope, seeing as the sub-trope implies the presence of the super trope.

Heck, some tropes can be sub-tropes of more than one super trope. This can be a shared aspect of them or actually combining the two tropes.

Compare Sister Trope.

Compare/Contrast The Same, but More Specific (when a distinction is not enough to make a separate trope).

Notable Sub-Tropes