A universal swing hinge assembly for a gravity-closing gate can be attached to a guardrail on either side of a guardrail opening. A hinge pin can be disposed through the universal swing hinge assembly and gravity-closing gate for attaching the gravity-closing gate thereto. The universal swing hinge assembly can have a C-configuration that allows the gravity-closing gate to swing open in either direction from a lowest neutral position. A recess of the universal swing hinge assembly can have an angled hinge face that opens towards the guardrail opening. In operation, the angled hinge face can cause the gravity-closing gate to rise from the lowest neutral position when the gravity-closing gate is opening, and the angled hinge face can cause the gravity-closing gate to return to the lowest neutral position when closing.