The mechanic that does most of the work in Human Design is the distinction between defined and undefined centres, and it explains why gate entries matter in practice.
A channel is complete when both of its gates are activated in a chart. A completed channel defines the two centres it connects. A defined centre is held to operate consistently and reliably; it is a fixed part of the person. An undefined or open centre has no such consistency of its own.
The system's central psychological claim follows. Open centres are held to take in and amplify whatever they encounter in others. A person with an undefined Solar Plexus is said to absorb the emotional weather of the room and to experience it as their own; a person with an undefined Sacral is said to take in and amplify other people's life force and to mistake borrowed energy for stamina. Human Design calls this conditioning, and treats the open centres as the places where a person is most susceptible to becoming someone they are not.
The inversion is what makes it distinctive. Openness is not weakness in this account. Open centres are where wisdom is said to accumulate over a life, precisely because the person has sampled so much variety there; the defined centres are reliable but narrow. The instruction is not to close the open centres but to stop identifying with what passes through them.
Every gate entry in this set should be read against that structure. A gate on its own is a half-channel and a potential; what the system says about a person depends on whether the other half is present, which is a matter of the whole chart rather than of any single gate.