A contract is a particular type of agreement that meets certain requirements to create legally binding obligations between parties that can be enforced by a court. Each country recognized by private international law has its own national legal system to govern treaties. While contract law systems may have similarities, they can differ significantly. As a result, many contracts contain a choice of law clause and a jurisdiction clause. These provisions define the laws of the contracting country and the country or other forum in which disputes are settled. Without explicit agreement on such issues in the treaty itself, countries have rules for determining treaty law and jurisdiction over litigation. For example, European Member States apply Article 4 of the Rome I Regulation to decide on the law applicable to the Treaty and the Brussels I regulation on competence. If a contractual guarantee or a minor term has been breached, it is unlikely that it can be terminated, although the other party can claim damages. Each contracting party must be a “competent person” with the force of law. The parties may be individuals (“individuals”) or legal entities (“companies”).
An agreement is reached if an “offer” is adopted. The parties must intend to be legally connected; and to be valid, the agreement must have both a correct “form” and a legitimate purpose. In England (and in jurisdictions using the principles of the English treaty), the parties must also exchange “counterparties” to create a “reciprocity of engagement,” as in Simpkins/Country.  Although the European Union is in fact an economic community with a number of trade rules, there is no `Community contract law`. In 1993, Harvey McGregor, a British lawyer and academic, developed a “contract code” under the auspices of the English and Scottish Law Commissions, which was a proposal to encrypt and codify the contractual laws of England and Scotland. This document has been proposed as a `treaty code for Europe`, but tensions between English and German lawyers have led to the failure of this proposal so far.  A Tang Dynasty contract recording the purchase of a 15-year-old slave for six pure silk bolts and five Chinese coins in commercial agreements is presumed that the parties intend to be legally bound, unless the parties explicitly state otherwise, as in a contractual document.