The paper investigates idempotent, reductive, and distributive groupoids, and more generally Ω-algebras of any type including the structure of such groupoids as reducts. In particular, any such algebra can be built up from algebras with a left zero groupoid operation. It is also shown that any two varieties of left k-step reductive Ω-algebras, and of right n-step reductive Ω-algebras, are indep...