It require at least one melee attack.
I don’t know exactly, the dodge bonus is affected by intelligence but a (3) melee (3) unarmed Zui Quan fighter get not only the crazy dodges but a crazy number of counters too!
Almost any enemy that gets too close will be insta-killed. It’s so convenient that you don’t even have to attack them directly! Just walk past the horde and watch as every zombie around you explode.