This Practice Note provides an overview of the essential components required to create a valid and enforceable contract: offer, acceptance, and consideration. This Practice Note defines each of these concepts in turn, identifies the conditions which must be satisfied for them to be deemed valid, and discusses their operation in various legal contexts. Subsequently, this Practice Note identifies which contractual relationships give rise to an assumption of an intention to create legal relations, and further, which categories of persons lack the requisite capacity to enter binding legal relations. Finally, this Practice Note considers the general principles of contract interpretation which apply in Ireland.