Building on a body of previous research by the author and colleagues in relation to multiple adverse childhood experiences (MACE), this paper addresses the question of ‘why multiples matter’ in relation to issues of cumulative adversity. Illustrative evidence is drawn from three research domains—epidemiology, multiple services use and child maltreatment—to demonstrate the collective weight of evidence to suggest a targeting of those children and families experiencing multiple adversities to diminish the effects of such adversities realised across the life course. Whilst the history of previous largely unsuccessful attempts to widen the range of children prioritised for intervention by child and family social workers might lead to pessimism in relation to their ability to respond to a MACE-informed public health agenda, there are clear possibilities for developing agency structures, assessment tools and social work practices directed towards meeting the needs of those sub-populations already prioritised by social workers: namely Children in Need, Children in need of Protection and Looked after Children.