Trover is a specialized form of trespass on the case, and was the last of the important personal actions to come into existence. Trover bears a close resemblance to the action of detinue sur trover, but was not derived from this action. Trover supplanted detinue, for the same reason that assumpsit did debt - namely, the existence of the common procedural difficulties in debt and detinue.

"The most curious feature of the action of trover is the fact that it is encumbered with more fictions than any other personal action. The declaration alleges a losing by the plaintiff and a finding by the defendant, but neither of these allegations need be proved. Furthermore, if a bailment is alleged as a means of indicating the manner in which the defendant acquired possession, it need not in modern times be proved. A refusal to surrender on demand is also often alleged in the declaration, but this allegation is likewise immaterial where the taking is tortious.

1 Vol. IV, Subject 8, Chapter II (The District Courts. Section 4. Statutory Provisions).

2 Id.

"The gist of the action is found in the allegation that the defendant 'converted the goods to his own use.' But oddly enough, even this allegation is also a sort of fiction; for if words mean anything a conversion to one's own use implies an appropriation under such circumstances as to result in benefit to the converter. But nothing is better established than that this is not necessary. Conversion in law does not mean acquisition of property. It is enough that the owner or person having the right to possession has, under conditions more or less clearly defined, been deprived of dominion over the goods. A withholding of possession under an inconsistent claim of title is sufficient." 3