For an agreement to become legally binding, the parties concerned must intend to create legal relationships. This means that the parties concerned understand that, if they do not comply with their obligations under the agreement, the other party retains the right to bring them to justice. The intention to establish legal relationships in a contract should not be implied, in particular in commercial agreements whose premeditation is generally presumed, unless the parties explicitly state otherwise. Contractual guarantees are less important conditions and are not fundamental to the agreement. They cannot terminate a contract if the guarantees are not fulfilled, but they can possibly claim compensation for the losses suffered. The fourth necessary element of a valid contract is legality. The basic rule is that the courts will not impose an illegal transaction. Contracts are only enforceable if they are concluded for the purpose of being legal and the parties intend to legally commit themselves in their agreement. An agreement between family members, with a member who covers the check, to go to dinner is legal, but will probably not be concluded with the intention of being a legally binding agreement.
Just as a contract for the purchase of illicit drugs is concluded by a dealer with all parties who know that what they are doing is contrary to the law and, therefore, not a contract applicable in court. For a contract to be valid, both parties must have the mental capacity to understand the terms of the contract and the consequences of the conclusion. Contracts that do not have clear, complete or clear conditions can fail due to lack of security. According to the doctrine of contract law, the rights and obligations arising from a contract are attached only to the parties to that contract, and only the parties to a contract may impose or enforce it against them.4 Reciprocity – the contracting parties had «a meeting of heads» on the agreement. This means that the parties have understood and agreed on the basic treatment and contractual conditions. There is no particular format to follow by a contract. Generally speaking, it contains certain explicit or tacit terms that form the basis of the agreement. These conditions may include contractual conditions or contractual guarantees. .