Regardless of the content of social benefits, the development of the welfare state has expanded opportunities for disputes about their distribution. These disputes involve rights that are “diffuse” in so far as they relate to small sums of money and large numbers of plaintiffs. By their very nature, they pit a private person, typically in isolation, against a institution owing benefit (a government department or an autonomous social security agency). The difficulty inherent in suing for an often “diffuse” right is thus compounded by the structural inequality between the legal and economic means of the institutional defendant and the private plaintiff. This raises questions about procedural rules. Do they provide the means to rebalance the case or do they continue to refer to the fiction that parties are equal before the judge, which traditionally governs the organisation of judicial proceedings? In other words, does legal process take account both of the nature of “diffuse” rights and of the structural disparity of the parties’ situations or does it presume that the latter, being equal in law, are equally capable of grasping the rules and using them for their benefit?