Why are actual licenses such powerful damages evidence?
Because they record what real parties genuinely agreed, rather than what an economist reconstructs from theory. A negotiated agreement carries the weight of a decision somebody actually made with money at stake, and juries and judges both respond to that.
That persuasiveness is exactly why courts examine them closely. An agreement offered as comparable is being used to say something about a different patent, a different product or a different commercial context, and the distance between the agreement and the case has to be bridged with evidence rather than assertion.
What does comparability actually require?
Technical comparability means the licensed technology is genuinely similar to the asserted claims — a judgment requiring someone competent in the field, not merely a reading of the agreement’s title. Economic comparability covers scope, exclusivity, field of use, territory, term, the commercial relationship between the parties, and how close in time the agreement sits to the hypothetical negotiation.
Neither is binary. Comparability is a matter of degree, and courts accept adjustment where an expert explains the basis for it. What fails is silent adjustment: applying a rate from a different technology or market without acknowledging the gap, or applying an unexplained discount that appears reverse-engineered from a desired result.
Can a settlement license be used as a comparable?
Sometimes, and it requires care. Agreements reached to end litigation reflect the cost and risk of litigation as well as the value of the technology, which courts recognize and which affects the weight they carry. They are not categorically inadmissible, and in some fields they are close to all the evidence that exists.
What a settlement license cannot do is stand unexplained. An expert relying on one needs to address the litigation context directly rather than presenting the figure as though it were a market rate arrived at by willing parties in ordinary commerce. Presenting it that way is an invitation to both a Rule 702 motion and a damaging cross-examination.
What if the only licenses cover an entire portfolio?
Then the analysis needs evidence that allows the asserted patent to be separated from the others, and this is the failure that produced the most striking recent outcome in patent damages. In 2025 an appellate court affirmed the exclusion of a damages expert who relied on a license covering multiple patents without apportioning the value of the asserted patent from the rest, and the resulting award was nominal.
The separation does not have to be perfect, and courts have not demanded precision that the evidence cannot support. It does have to be reasoned from something — relative technical importance, citation or usage evidence, the parties’ own contemporaneous treatment of the patents. Dividing the portfolio value evenly across its patents because that is arithmetically convenient is the version that gets excluded.
How is a lump-sum agreement turned into a royalty rate?
With difficulty, and only with support in the record. Deriving an implied per-unit royalty from a single payment requires knowing what sales volume the parties had in mind when they set it, and unless the agreement or the negotiation record establishes that, the figure is being supplied by the expert rather than by the evidence.
Recent authority has been pointed about this. Expert testimony that both parties understood a lump sum to reflect a particular per-unit rate needs something establishing that shared understanding — a term in the agreement, correspondence, testimony from the negotiators. An inference from the size of the payment is not that, and an opinion resting on it is exposed.
Do your own past licenses work against you?
Routinely, and companies are consistently surprised by it. Agreements signed years earlier, on terms nobody expected to matter, are discoverable and become the ceiling on what the same party can credibly claim later. A rate accepted once is difficult to argue was unreasonably low afterward.
The practical implication is for how licensing programs are run rather than how cases are argued. Every agreement is a future exhibit, including its recitals and including whatever was bundled in to close the deal. Structuring and documenting them with that in mind costs nothing at signature and is worth a great deal later.