The structures drilled to‐date in the NW Witch Ground Graben area have been assigned to two broad categories:(i) Upthrown traps with four‐way dip closure or tilted fault blocks, generally located on the franks of the graben: and(ii) Downthrown traps with closure against a major fault, located downthrown on the main graben border fault systems.Many of the downthrown traps are in fact combination traps, having upthrown fault‐seal and/or stratigraphic elements.A study of trap settings in the NW Witch Ground Graben has led to the following conclusions:1. The success rate for encountering hydrocarbons in upthrown traps and downthrown traps is very similar.2. The common belief that the footwall seal is the most critical element of a downthrown trap is questionable.3. Modern seismic data reveals that a high proponion of unsuccessful exploratory wells were not located on a closed structure. The proportion is similar for upthrown and downthrown trap targets alike.4. There is a lesser chance of the reservoir being absent, or there being no migration route to the trap, in downthrown structures, compared with upthrown ones.5. Carboniferous sediments can be a footwall seal for a downthrown trap in one location, and a reservoir for hydrocarbons in another.6. The structural evolution of the NW Witch Ground Graben, within a framework of three intersecting fault trends, has been ideal for the development of downthrown traps. The distribution of a hydrocarbon source rock, the timing of hydrocarbon migration into these structures, and the suitable distribution of sealing strata adjacent to the border fault of the structure, have also been critical.