A three-piece stabilizing and adjustable bracket member for constructing an A-frame style swing set/play set system, ideal for erection by a do-it-yourself builder. The system includes a first cross beam securing member that features a face plate for selectively mounting a pair of angularly disposed leg support members. The face plate is provided with a single pivotal fastener and plural openings spaced an equal distance from the single pivotal fastener, such that the leg support members may be selectively pivoted about the fastener then secured in one or a pair of the plural openings.