Damages are proved by expert modeling in most substantial commercial disputes, and the model’s structure determines both the figure and its vulnerability.

Lost profits. Revenue that would have been earned but for the wrong, less avoided costs. Requires a but-for world, and its credibility rests on the baseline — historical performance, comparable businesses, budgets prepared before the dispute, or a yardstick from unaffected operations.

Benefit of the bargain. The difference between what was promised and what was received, common in acquisitions where the target underperformed the representations.

Unjust enrichment or disgorgement. The defendant’s gain rather than the plaintiff’s loss, available for some claims including trade secret misappropriation and breach of fiduciary duty. Requires apportionment between the gain attributable to the wrong and that attributable to the defendant’s own contribution.

Reasonable royalty as a floor in intellectual property and trade secret cases, derived from comparable licenses or a hypothetical negotiation.

Discount rates and pre-judgment interest frequently move the result more than the underlying projections and receive far less attention.

Common attacks. Failure to deduct avoided costs; double counting across theories; projections inconsistent with contemporaneous business plans; and extending the damages period beyond any period the plaintiff could have sustained the business.