Also known as: impracticability · impracticable · commercial impracticability
Written by attorneys · grounded in primary & secondary sources — see below
A doctrine discharging a party's contractual duty when performance becomes impracticable without fault due to a supervening event whose nonoccurrence was a basic assumption of the contract.
Daniel Diaz sought to represent hundreds of investors in a securities suit against a single brokerage. The investors were scattered across multiple states with no centralized list readily available. The court found joinder of every investor would be impracticable and certified the class under the numerosity requirement.
Dillon Energy agreed to deliver fuel daily to Dakota Industries using a single mountain pass. An avalanche caused an indefinite official closure with no feasible alternate route at comparable cost. The closure discharged Dillon Energy's delivery duty under the contract.
Select any source to read its text and confirm it supports the definition.
Dominic Drake purchased a lot subject to covenants requiring approval by a named two-person committee. One member died and the other refused to serve with no succession mechanism in place. The court modified the covenant because locating or reconstituting the committee had become impracticable.
Decker Electronics operated a plant emitting noise into neighboring residential property owned by Doris Duffy. Installing effective sound barriers would have required prohibitive structural changes to the facility. The court weighed the impracticability of avoiding the invasion when assessing whether the conduct was unreasonable.
Duarte Shipping contracted to transport cargo using a specific type of specialized vessel that later became unavailable due to regulatory restrictions. A commercially reasonable substitute vessel was readily obtainable. Duarte Shipping was required to tender and the buyer was required to accept performance by the substitute carrier.
Daphne Doyle created a trust for a specific charitable purpose that later became impossible to achieve because of changed community conditions. The trustee petitioned to modify the purpose to a similar charitable use. The court authorized the modification because the original purpose had become impracticable.
The party must demonstrate that performance became impracticable without its fault because of a supervening event whose nonoccurrence was a basic assumption of the contract. The doctrine applies even when performance remains physically possible if the event fundamentally alters the nature of the required performance.
No. Ordinary or even significant cost increases fall within the risks allocated by a fixed-price contract and do not discharge the duty. Only an extreme cost increase that transforms the essential nature of the performance can support the defense.
When the contract itself specifies that a particular event terminates the duty, that clause controls and the party need not separately prove impracticability. The doctrine supplies a background rule only when the parties have not expressly allocated the risk of the supervening event.
No. Temporary impracticability suspends the duty only while the condition exists. The duty is not discharged unless resumption of performance after the condition ends would be materially more burdensome than originally contemplated.
…. . invalidating legislation on the basis of their view on that question at the moment of decision, a practice which has proved impracticable in other fields.'" Id. , at 240-241 (quoting United States ex rel. TVA v. Welch , 327 U. S. 546, 552 (1946)); see Berman, supra , at 32 ("[T]he legislature, not the judiciary, is the…