A multicomponent polyurethane/vinyl ester hybrid foam system for forming a gradient foam with soft and rigid foam regions, with a polyol component (A), a polyisocyanate component (B), and a component (C), which contains a catalyst for the polymerization of the vinyl monomer, with the polyol component (A) containing, as vinyl monomer, a mixture of vinyl esters of at least one polymerizable hydroxyvinyl ester and at least one branched, at least trifunctional, polymerizable vinyl ester, and the polyisocyanate component (B) containing a thermally activatable free radical-forming agent as catalyst for the polymerization of the vinyl monomers, with the proviso that the proportion by weight of the vinyl ester mixture is greater than the proportion by weight of the at least one polyol as well as the proportion by weight of the at least one polyisocyanate.