In classic science fiction, 'the weaklings' could be a term. Consider a story where there is a race of super - intelligent aliens and humans are seen as the weaklings, having no power to resist their control. The humans in this case are at the mercy of the more powerful aliens and are often exploited because of their lack of power.
Well, in some older science fiction, 'the subjugated' was used. In a story where a planet has been conquered by an intergalactic empire, the native population becomes the subjugated. They have no power to change their situation, no political rights, and are forced to follow the rules and demands of the conquering force.