Descending Acquiescing Coalitions

Descending Acquiescing Coalitions or DAC is a voting system devised by Douglas Woodall for ranked ballots. It is equivalent to Descending Solid Coalitions, except that sets are scored not by the number of voters solidly committed to them, but by the number of voters acquiescing to them. A voter "acquiesces" to a set of candidates if he does not strictly prefer any candidate outside of the set to any candidate within the set.

Unlike DSC, DAC does not satisfy the Later-no-harm criterion, but it does, unlike DSC, satisfy the Later-no-help criterion.

When no voter uses equal rankings or truncation, then DSC and DAC give the same results.