This paper argues for a form of 'adaptive assessment' of cumulative socioeconomic impacts of resource development. We employ concepts related to complexity, wicked problems, boundary objects and adaptive management. The complexity of such an assessment task is illustrated here with examples from a case that our research team has studied for the past three years - four megaprojects totalling $60 billion to produce onshore natural gas in an agricultural area of Queensland, Australia with 40,000 residents.