What are litigation costs for a plaintiff in a personal injury action?

In contrast to the American rule that parties to a lawsuit ordinarily pay their own attorney fees, litigation costs have been traditionally awarded to the prevailing party. Costs are allowances which are authorized to reimburse the successful party to an action or proceeding, and are in the nature of incidental damages to indemnify a party against the expense of successfully asserting his rights. (Purdy v. Johnson (1929) 100 Cal.App. 416, 418, 280 P. 181 ; see

[370 P.3d 1000]

1033.5 [costs include filing fees, ordinary witness fees, costs related to recording and transcribing depositions, and certain costs of preparing exhibits].) The theory upon which [costs] are allowed to a plaintiff is that the default of the defendant made it necessary to sue him, and to a defendant, that the plaintiff sued him without cause. Thus the party to blame pays costs to the party without fault. (Purdy v. Johnson, at p. 418, 280 P. 181.)