Common law provinces In Canada's common law provinces and territories three components are required for the formation of a valid contract: offer, acceptance, and consideration. Additionally, the parties themselves must have the legal capacity and the intention to create legal relations. Offer and acceptance An offer must be some indication of the offeror to the offeree that he is prepared to form a binding legal agreement. Intention is measured objectively. Commercial deals are presumed to be of a legal nature while an agreement made between family members or in a social engagement is presumed not to be of a legal nature. Acceptance is the promise or act on the part of an offeree indicating a willingness to be bound by the terms and conditions contained in an offer. An acceptance must be an absolute and unqualified acceptance of all the terms of the offer: Sec.7(1). If there is any variation, even on an unimportant point, between the offer and the terms of its acceptance, there is no contract. An acceptance is only contractually valid if the proposal to which response is made is an offer capable of acceptance. Often, when two companies deal with each other in the course of business, they will use standard form contracts. Often these standard forms contain terms which conflict (e.g. both parties include a liability waiver in their form). The 'battle of the forms' refers to the resulting legal dispute arising where both parties accept that a legally binding contract exists, but disagree about whose standard terms apply. Such disputes may be resolved by reference to the 'last document rule', i.e. whichever business sent the last document, or 'fired the last shot' (often the seller's delivery note) is held to have issued the final offer and the buyer's organisation is held to have accepted the offer by signing the delivery note or simply accepting and using the delivered goods. An offer must also be distinguished from an invitation to treat, which is where one party invites another party to consider a deal. Advertisements are also considered invitations. Exceptions are made in circumstances where a unilateral contract for performance is offered or where the advertisement is sufficiently serious about its promise such as in the famous Carlill v. Carbolic Smoke Ball Co.. In the similar case of Goldthorpe v. Logan, [1943] 2 DLR 519 (Ont CA) an "absolute and unqualified" guarantee to safely remove all