Abstract: A modular guardrail system relates to a set of interconnected beams that each fit into pairs of detachable bases, thus allowing for the creation, adjustment, and removal of a variety of configurations of temporary fence-style barriers. Each guardrail section may include two vertical posts, one on each end of each guardrail section, connected by a set of horizontal beams and, in some cases, a horizontal toeplate. Adjacent guardrail sections share a common base, thus allowing for the chain assembly of an extended barrier. The base that connects to the guardrail sections may include several vertically-oriented brackets that may slide into the different guardrail posts. The placement of the vertical brackets upon the base is selected so that each of the attached guardrail sections can be arranged independently of one another in any direction. The vertical brackets may be rotatably attached, thereby allowing for more flexible arrangements of the guardrail sections.