As stated in Alford v. Canada, 1997 CanLII 868 at paragraph 37, there are two types of actionable conspiracy in Canada:
In the first form, the conspiracy is where two or more persons combine for the predominate purpose of causing injury to another. In this form of conspiracy, the unlawfulness is in the purpose of the scheme; accordingly, lawful acts become unlawful due to the intent to cause unjust injury to another person. This form of conspiracy remains somewhat controversial as acting in efforts to improve one's own interests, is generally legitimate.
In the second form, being the tort of conspiracy to injure by unlawful means, oftentimes the bringing of a conspiracy legal action can be redundant and unnecessary such as in circumstances where the unlawful means exercised by the conspirators was in itself tortious. In such circumstances, upon proving the tortious unlawful means, known as a 'nominate tort', proving the elements of conspiracy often becomes unnecessary; yet in some circumstances, pleading conspiracy, and seeking to prove same, may be a worthy task. In this respect, the Supreme Court of Canada refused to strike claims for conspiracy where other torts were pleaded; see: Hunt v. Carey Canada Inc.,  2 S.C.R. 959.
The elements of each type of conspiracy were well described in Dale v. Toronto Real Estate Board, 2012 ONSC 512 as:
 There are two types of civil conspiracy. First, there is a conspiracy where the predominant purpose of the defendants is to cause injury to the plaintiffs, regardless of whether the means employed are lawful or unlawful. Second, there is a conspiracy where the conduct of the defendants is unlawful, is directed toward the plaintiff alone, and the defendants should have known that, in the circumstances, injury to the plaintiff was likely to result.
 More particularly, the elements of “predominant purpose conspiracy” require the plaintiff to establish that: (1) the defendants acted in combination, that is, in concert, by agreement or common design; (2) the predominant purpose of the defendants was to intentionally harm the plaintiff; and (3) the defendants' conduct caused harm to the plaintiff. The elements of “unlawful means conspiracy” require the plaintiff to establish that: (1) the defendants acted in combination, again that is, in concert, by agreement or common design; (2) the defendants committed some unlawful act such as a crime, a tort, or breached some statute; (3) the defendants conduct was directed towards the plaintiffs; (4) the defendants knew or ought to have known that injury to the plaintiffs was likely to occur from their unlawful act; and (5) the defendants' unlawful conduct in furtherance of their conspiracy caused harm to the plaintiff.
Liability Among Conspirators
An important consideration in any conspiracy action involves the doctrine of joint liability. This is especially important where certain conspirators may be better financially positioned to pay compensation as a joint tortfeasor despite merely watching from the sidelines while the wrongful acts being performed by other conspirators. In this respect, the law treats each conspirator as jointly liable regardless the level of involvement in the actual wrongs, even if the wrongs performed in furtherance of the conspiracy were unbeknownst to all conspirators; so long as any conspirators act wrongfully towards the purpose of the conspiracy, all conspirators remain as jointly liable as joint tortfeasors. This principle was described well in Bains v. Hofs, 1992 CanLII 264 at page 9:
In The Law of Torts, 7th ed. (The Law Book Company Ltd.,) c. 11, p. 229, Fleming discusses the concept of joint tortfeasors:
"A tort is imputed to several persons as joint tortfeasors in three instances, viz. agency, vicarious liability, and concerted action...The critical element of the third is that those participating in the commission of the tort must have acted in furtherance of a common design. There must be 'concerted action to a common end', not merely 'a coincidence of separate acts which by their conjoined effect cause damage' (The Koursk (1924) P. 140 at 156). Broadly speaking, this means a conspiracy with all participants acting in furtherance of the wrong, though it is probably not necessary that they should realise that they are committing a tort. All persons acting in pursuance of a common end, being thus identified with each other, are accordingly responsible for the entire result and so it was laid down in 1612 that 'all coming to do an unlawful act, and of one party, the act is the act of all the same party being present' (Heydon's Case, 77 E.R. 1150 at 1151)."
It is the question of concerted action that arises in the case at bar. On this issue, the learned author continues on to say at p. 230:
"While the requisite degree of participation has not been precisely defined in modern decisions, there is a cogent support both in principle and ancient authority for the suggestion that it may well correspond with the description attached by the criminal law to principles in the first and second degree. This would include, besides the actual perpetrator, anyone who 'aids and abets', whether or not he actively intervenes. Knowingly assisting, encouraging or merely being present as a conspirator at the commission of the wrong would suffice."
Thus, one who knowingly assists or encourages another to commit a tort, or one who is merely present as a conspirator in the wrong that is done, is, in law, a joint tortfeasor.