The key to modelling multi-party cases is to recognise that in legal terms, they represent a series of separate cases heard at the same time. The number of cases is (number of defendants *2)-1. For case provisioning typically only I combined model is necessary, but potentially the range of models that might be required or could be made is number of defendants +1.

Litigation Roulette
The law (in England at least) has always frowned upon gambling and treated sporting wagers as unenforceable. This extended to some activities not commonly