The paper addresses the uncertainty that prevails if courts have to decide about the fairness of suretyships. They do not know whether creditors will refrain from giving a credit in similar situations or increase the interest rate. Similarly, they do not know to what extent strict rules will ruin the lives of sureties. Several strategies how to deal with this uncertainty are analysed like the ignorance of adverse effects, the minimax-strategy and the choice of an overprotective or an underprotective rule. It will turn out that an underprotective rule creates a smaller risk than an overprotective rule.
European Review of Private Law