A breach is fundamental when it jeopardizes the interest of the innocent party.
FUNDAMENTAL BREACH OF CONTRACT:
Art. 8:103 PECL:
COMMON LAW: When it comes to liquidated damages clauses, according to common law, the clauses that can be enforceable are the ones whose value is either equal or below what the judge would estimate. No penalty clauses, or at least they are not enforceable. Only point 1 and 3 can be enforced in common law jurisdiction. Because there is a risk of abuse.
Civil Law:We do allow parties to compensate with a higher amount of money than the ones that would have been assessed by the judge for the compensation of the damages. But we do have some legal protection to avoid abuse. The judge can reduce the amount whether “it is manifestly excessive” → there are criteria to establish that. If they are above a certain threshold they are considered excessive. It is the way in which the civil law jurisdiction can allow the possibility of penalty clauses