[MunchkinMan]

The term "vice versa" means to flip the main components of the previous phrase. In this case, those main components are the Monster's Level and the Level of the player fighting it. That means the long form of the phrase would be, "If the Monster's Level is higher than yours, its Level doesn't count, and if your Level is higher than the Monster's, your Level doesn't count."

For raw numbers: If you're Level 5 or lower, the Monster doesn't add its Level to its combat strength but you add your Level to your own combat strength; if you're Level 7 or higher, you don't add your Level to your combat strength, but the Monster still adds its Level to its combat strength. If you're Level 6 then you both get to add your Levels to your combat strengths.