19 Protection of reasonable reliance and expectations

This is an aspect of security which appears in different parts of the DCFR. It first appears in relation to contract formation. It may happen that one party does not intend to undertake an obligation when that party's actions suggest to the other party that an obligation is being undertaken. A typical case is where an apparent offer is made by mistake. If the other party reasonably believed that the first party was undertaking the obligation as apparently stated, the other party's reliance will be protected in most legal systems. This may be achieved either by using the law on non-contractual liability for damage caused to another or, more simply, by holding the mistaken party to the outward appearance of what was said. The protection of reasonable reliance and expectations is a core aim of the DCFR, just as it was in PECL. Usually this protection is achieved by holding the mistaken party to the obligation which the other party reasonably assumed was being undertaken. Examples are the objective rules on interpretation1., the restriction of avoidance for mistake to cases in which the non-mistaken party contributed to the mistake, should have known of it or shared it2. and the rule that imposes on a business which has failed to comply with a pre-contractual information duty such obligations under a contract as the other party has reasonably expected as the consequence of the absence or incorrectness of the information.3.