An energy gate, which is also known as an energy fence, functioned as a security measure. It used a static or electromagnetic field to prevent unauthorized entry into sensitive locations. These locations included facilities like detention centers and power generators, as well as areas rendered dangerous by toxins or disease. A notable example is its use in containing the bioplague within a sector of the world Radnor. Often constructed with energy bars, energy gates were typically controlled remotely. The energy cage shared a technological basis with the energy gate.