Reasonable royalty and lost profits
U.S. patent law sets a reasonable royalty as the floor for compensation, usually framed as what the parties would have agreed to in a hypothetical negotiation just before infringement began. Lost profits are available when the patent owner can show it would have made the sales but for the infringement, which calls for detailed proof about the market that many owners find hard to supply. Apportionment runs through all of this: when the patented feature is one part of a larger product, damages generally have to reflect the value of that feature rather than the whole device. Design patents follow a separate rule that can reach the infringer's profits on the article of manufacture.
Timing limits and marking
Damages generally cannot be recovered for infringement that occurred more than a fixed period before the suit was filed, so delay can cost money even when the claim itself survives. Whether the patent owner marked its products, including through virtual marking, or gave actual notice of infringement affects when damages begin to accrue. Patents with only method claims, and owners who sell no products, may be treated differently on marking. Enhanced damages are possible for egregious willful conduct at the court's discretion, and attorney's fees may be awarded in exceptional cases.
Building or answering a damages case
Damages evidence comes from licenses, sales data, cost records, market studies, and testimony from retained economists. Owners should collect their licensing history, product sales, and marking records early. Accused companies should understand their own revenue and cost data for the accused feature and look at what alternatives were available at the time. In a first meeting we discuss which theories fit the facts, what records exist, and how a realistic range of exposure affects settlement planning. Earlier licenses on the same patent often become the most closely examined evidence, because they show what parties have actually paid.
