Русско-англо-русский юридический словарь

Liquidated damages (also referred to as liquidated and ascertained damages) are damages whose amount the parties designate during the formation of a contract for the injured party to collect as compensation upon a specific breach (e.g., late performance). [...] At common law, a liquidated damages clause will not be enforced if its purpose is to punish the wrongdoer/party in breach rather than to compensate the injured party (in which case it is referred to as a penal or penalty clause). (Wikipedia)

In the United States, a liquidated damage clause is intended to estimate damages in the event of non-performance or breach of contract. [...] The intent of liquidated damages is simply to measure damages that are hard to prove once incurred. If the liquidated damages are disproportionate, they can, however, be declared a penalty. The clause is then void, and recovery will be limited to the actual damage that results from the breach. [...]

In civil law countries, the attitude toward contractual penalties is quite different from the common law approach. The Napoleonic Code, upon which most civil codes are based, allowed for penalties to encourage performance of contractual obligations. (This is the precise rationale that is rejected in the United States.) (lexology.com)

Russia: The New Civil Code from 1994 allows for both liquidated damages and contractual penalties in contracts. Both can be reduced by the court if obviously disproportionate to the actual loss. (lexology.com)

Overall, European civil law jurisdictions generally distinguish between liquidated damages and penalty clauses and consider both of them enforceable, and allow the possibility that the court may mitigate the amount of a penalty in case of excessiveness or partial performance. (internationallawoffice.com)