In [30], Tardos studied special delta-matroids obtained from sequences of
Higgs lifts; these are the full Higgs lift delta-matroids that we treat and around which
all of our results revolve. We give an excluded-minor characterization of the class of
full Higgs lift delta-matroids within the class of all delta-matroids, and we give similar
characterizations of two other minor-closed classes of delta-matroids that we define using
Higgs lifts. We introduce a minor-closed, dual-closed class of Higgs lift delta-matroids
that arise from lattice paths. It follows from results of Bouchet that all delta-matroids can
be obtained from full Higgs lift delta-matroids by removing certain feasible sets; to address
which feasible sets can be removed, we give an excluded-minor characterization of deltamatroids
within the more general structure of set systems. Many of these excluded minors
occur again when we characterize the delta-matroids in which the collection of feasible
sets is the union of the collections of bases of matroids of different ranks, and yet again
when we require those matroids to have special properties, such as being paving