14 In exercising this discretion, the Court must act judicially, and is guided in doing so by well-established legal principles, including the 'ordinary rule' that a successful litigant is, prima facie, entitled to an award of costs, unless there are special circumstances warranting a departure from the rule: O'Sullivan v Crown in Right of the State of New South Wales (Department of Education and Training) (2003) 128 IR 158 at [198] - [199], Powerlan Ltd & Anor v Squires (No 2) [2007] NSWIRComm 68.
15 It is certainly within the discretion of this Court to apportion costs, as suggested by the applicant, in instances where a party is only partially successful in relation to the final determination of the Court. (See for example O'Sullivan v Crown in Right of the State of New South Wales [196] - [202], Powerlan v Squires [14] - [18], Oshlack v Richmond River per McHugh J at pp 95-97 and Kirby J at 120-122, Ruddock & Ors v Vadarlis & Ors (No 2) [2001] FCA 1865, per Black CJ and French J, at pp 234-5; Crump & Ors v Equine Nutrition Systems Pty Ltd T/A Horsepower & Anor (No 2) [2007] NSWSC 25 at [35] - [44]). In NRMA Ltd & Ors v Morgan & Ors (No 3) [1999] NSWSC 768, Giles J referred to the "fairly well established" principles regarding orders as to costs in this regard at [24] - [25].
If a party fails on some issues, the circumstances may make it reasonable that he be deprived of the costs of those issues, or even be ordered to pay the other party's costs of those issues. For this purpose, issues may be issues in a pleading sense of bases of claim, or may be disputed questions of fact or law. But it must be remembered that parties should not be dissuaded by the risk of costs from canvassing all issues which might be material to the decision in the case, and unless particular issue or group of issues is clearly dominant or separable from the balance of the proceedings it will ordinarily be appropriate to award the costs of the proceedings to the successful party without attempting to differentiate between the issues on which he was successful and those on which he failed. It is sufficient to refer to Cratazzo v Lombardi (1975) 13 SASR at 12; Hughes v Western Australian Cricket Association (1986) ATPR 40-748 at 48, 136; Dodds Family Investments Pty Ltd v Lane Industries Pty Ltd (1993) 26 IPR 261 at 271-2; and Waters v P C Henderson (Australia) Pty Ltd (NSWCA, 6 July 1997, unreported).