The nature of a transaction determines the nature of the applicable contract law. The general contract law described above applies to transactions such as service contracts and sales of real estate. However, contracts for the sale of goods are governed by Article 2 of the CSA, which has been adopted, at least in part, in each State. The CSD defines „goods“ as all things that are mobile at the time of sale. The performance obligation of many contracts is subject to the fulfilment of a specific condition or commitment. A condition is an act or event, with the exception of a period of time, concerning an obligation to perform a promised performance defined in a contract. A condition can be considered as a qualification based on a promise. A promise or obligation is absolute or unconditional if it does not depend on external events. Nothing but a schedule is necessary to make its performance due. When the time comes to respect an unconditional commitment, the immediate benefit is due. A dependent or conditional commitment is only effective when an external event has been reported by the parties. An implied condition is one that the parties should reasonably have understood in order to be part of the contract, because it is implied. The principles underlying an implied contract are that no person should receive unfair benefits at the expense of another person, and a written or oral agreement is not required to achieve fair play.
For example, the implied warranty is a kind of tacit contract. When a product is purchased, it must be able to perform its function. A new refrigerator must keep the food cool or the manufacturer or seller has not fulfilled the conditions of a tacit contract. Partial performance If the defendant has not concluded the performance of a contract in accordance with its conditions, the claimant may claim the damage that compensates him to the extent that the contract had been fully fulfilled. The usual measure of damage is the reasonable effort of completion. Completion is intended to do the same work, if possible, that does not involve unreasonable economic waste. The victim does not automatically have the right to recover the difference between the contract price and the amount that would cost the completion of the work in the event of an infringement after partial performance; he or she is entitled to recover this amount only if completion actually takes place at higher costs. . . .