Restatement 
§152, When Mistake of Both Parties Makes a Contract Voidable (Rules, 
p. 188)
  - Fact is a basic 
  assumption on which the contract was made
 
  
    - If the assumption 
    is just that it will make money, this usu. isn’t enough
 
    
  - Both parties must 
  be mistaken
 
  - Must have been in 
  existence at time K was made (otherwise, impracticability)
 
  - K is voidable by 
  adversely affected party unless he bears risk under §154.
 
  - Determination as 
  to material effect considers any relief by way of reformation, restitution, 
  or otherwise.
 
Restatement 
§154, When a Party Bears the Risk of a Mistake—How to Apportion Risk
Party bears risk of mistake 
when:
      - It is allocated 
      to him by agreement
 
      - He knew at time 
      of K that he had insufficient knowledge but acted anyway, OR
 
      - Court reasonably 
      allocates risk to him.
 
 
Remedy:
  - If mutual mistake 
  amounts to just a written error, appropriate remedy is to reform K to 
  express parties’ actual intent
 
  - Normally, recission 
  and restitution as appropriate
 
  - Courts are inconsistent 
  in their outcomes with these cases
 
Allocation 
of Risk by Agreement
LENAWEE 
COUNTY BOARD OF HEALTH V. MESSERLY (P. 634) 
Messerly’s sold land containing apartment building to the Pickleses, 
intended to be investment property, and later discovered it was unfit 
for human habitation due to sewage system installed by their predecessor 
in title. Messerlys sued for foreclosure; Pickleses counter-sued for 
rescission due to mutual mistake. 
For the Messerlys. No rescission granted.
  - Things seemed about 
  even so courts were looking for something that would tip the balance 
  one way or the other.
 
  - Sherwood v. 
  Walker. Barren cow. Court found mutual mistake b/c different 
  in nature (not just value).
 
  
    - Nature/Value distinction 
    no good any more – to intertwined
 
    
  - Looks to Restatement 
  §152
 
  
    - Material effect 
    on performance since lease was to be paid by property’s income
 
    
  - Looks to Restatement 
  §154(a).
 
  
    - Finds “as is” 
    clause sufficient to allocate risk to Pickleses by agreement.
 
UNILATERAL 
MISTAKE
When one party is mistaken, 
there is generally no defense to performance, save a few exceptions.
Restatement 
§153, When Mistake of One Party Makes a Contract Voidable (Rules, p. 
188)
Where a mistake goes to a 
basic assumption and has a material effect on performance, 
you can void if you do not bear the risk under §154 AND
  - The mistake would 
  make the K unconscionable OR
 
  
    - Unconscionable: 
    severe enough to create substantial loss
 
    
  - The other part had 
  reason to know or caused the mistake
 
WIL-FRED’S, 
INC. V. METROPOLITAN SANITARY DISTRICT (P. 643) 
Contractor(P) submitted bid that was like way lower than next lowest 
bid. Realized it was too low, subcontractor had made a $150,000 mistake 
on a $200,000 bid. Tried to withdraw, but it couldn’t. Sub said it’d 
be bankrupted if it had to perform. Contractor said it would suffer 
substantial hardship. K is rescinded.
  - Conditions of rescission 
  for unilateral mistake:
 
  
    - Mistake relates 
    to material feature of contract
 
    - Occurred notwithstanding 
    use of reasonable care
 
    
      - Quick response to 
      mistake
 
      
    - Unconscionable: 
    Grave consequences
 
    
    - Other party can 
    be placed in status quo
 
    
      - Court thinks city 
      should have known b/c of disparity of bids (as opposed to Drennan)
 
      - Contract hadn’t 
      been formally awarded. School could have awarded K to next lowest bidder
 
      
  - Due care and status 
  quo requirements not in the Restatement. They are risk assessment factors. 
  Court’s way of dealing with §154.
 
  - Why did Wilfred 
  sue so fast instead of not performing on K and letting District sue 
  for breach?
 
  
    - K hasn’t been 
    performed, so its easier for other party to be placed in status quo, 
    and the filing of the preliminary injunction held everything. This was 
    terrific lawyering. They got into court before district could dismiss 
    all other bidders.
 
IMPOSSIBILITY, 
IMPRACTICABILITY, FRUSTRATION OF PURPOSE
Relate to changes made after 
K is formed but before at least some part of performance is made. All 
Qs of law. 
Remedy: 
  - If you prevail, 
  your obligation under K is suspended. No obligation to perform. Pleader 
  is excused.
 
  - The other party 
  is left without remedy, isn’t placed in situation it was in before 
  contract. No restitution.
 
Impossibility
Almost exclusively applied 
to personal service Ks and sale of unique goods b/c everything else 
has a substitute.
TAYLOR 
V. CALDWELL (1863) (P. 653) 
P rented music hall for performance. Hall burns down. 
Court finds impossibility, b/c neither party at fault.
  - Today, we could 
  ask D to pay for concert to be held at another concert hall. But maybe 
  every concert hall is unique?
 
Impracticability 
& Frustration of Purpose
Restatement 
§261, Discharge by Supervening Impracticability (Rules, p. 204)
  - Party seeking discharge 
  was not at fault
 
  - Non-occurrence of 
  event was a basic assumption of K
 
  
    - NOT market downturn
 
    - NOT war
 
    - NOT natural disasters, 
    esp. if it is reasonably foreseeable (e.g. hurricane in FL)
 
    
  - (unless language 
  or circumstances indicate the contrary).
 
 
Frustration of Purpose: 
change in circumstances renders K meaningless by taking away primary 
purpose of K. In order to plead this, you have to say that you have 
no use for K anymore.
Restatement 
§265, Discharge by Supervening Frustration (p. 205)
  - Purpose must be 
  “principle purpose”
 
  - Frustration must 
  be substantial
 
  - Party seeking discharge 
  is not at fault
 
  - Non-occurrence of 
  event was a basic assumption of K
 
UCC 
§ 2-615: Excuse by Failure of Presupposed Conditions
Delay or non-delivery is not 
breach if performance as agreed has been made impracticable by occurrence 
of event upon which non-occurrence was a basic assumption of K.
Profitability 
not principal purpose. KARL WENDT FARM EQUIPMENT CO. V. INTERNATIONAL 
HARVESTER CO. (1991) (P. 655) 
Dramatic downturn in farm equipment market caused D to sell assets, 
making it unable to perform under dealer agreement with P. P sues for 
breach. Impracticability is invalid defense.
  - Impracticability
 
  
    - Not without fault: 
    IH responded by selling assets
 
    - Market shifts almost 
    never allow for impracticability b/c parties entering into K assume 
    market will move. 
 
    
      - Amount of financial 
      loss irrelevant.
 
      
  - Frustration of Purpose
 
  
    - Profitability is 
    not a principal purpose under §265.
 
    
      - K defines purpose 
      as “establish a dealership”
 
      - Would make Restatement 
      meaningless, since profitability could be seen as primary purpose of 
      every K
 
      
  - Termination Provision
 
  
    - Indicated how parties 
    intended to allocate loss and end agreement
 
    
  - Reduction in Product 
  Lines
 
  
    - Not intended by 
    parties as a way out of the K
 
Foreseeability 
of occurrence. OPERA COMPANY OF BOSTON, INC. V. WOLF TRAP FOUNDATION 
FOR THE PERFORMING ARTS (P. 664) 
Contract whereby D was to supply lighting for P’s performance. Thunderstorm 
causes power outage and D cancelled the performance. 
D not liable.
  - Scott: Disagrees 
  with ruling. Foreseeable that this could happen. Thunder storms common 
  in this area.
 
Substantial 
Frustration of Purpose. MEL FRANK TOOL & SUPPLY, INC. V. 
DI-CHEM CO. (P. 668) D leased building from P in which he stored 
chemicals. City ordinance passed after K is formed that prevents DiChem 
from storing hazardous chems in warehouses. D wants out of K. 
K is enforceable.
  - Frustration of 
  Purpose: Principal purpose not substantially frustrated. 
 
  
    - Property can still 
    be used as a warehouse for non-hazardous chemicals.
 
    
  - Force Majeure 
  Clause: Clause excuses performance under certain circumstances (Acts 
  of God, Gov’t regulation, etc.) – applicable to performance Ks, 
  but not payment Ks
 
  - Change in Law as 
  grounds to void
 
  
    - Depends on foreseeability 
    of the change
 
    - Can’t be collusive
 
modification
Requests for modification of 
K post-formation but during or pre-performance. 
Common Law: 
modification isn’t enforceable w/o fresh consideration, but court 
will look all over the place to find it. 
R2, 
§ 73, Performance of Legal Duty
Performance of legal duty owed 
to promisor which is neither doubtful nor subject of honest dispute 
is not consideration, but similar performance is consideration if it 
differs materially from what was required by duty in way which reflects 
more than pretense of bargain. 
R2 
§ 89, Modification of Executory Contract 
(A contact in which some performance remains to be done by one or both 
parties.)
Performance modifying duty 
under K not fully performed on either side is binding
If modification is fair 
and equitable in view of circumstances not anticipated by parties when 
K was made, or
To extent provided by statute, 
or
To extent that justice 
requires enforcement in view of material change of position in reliance 
on promise. 
 
Where Modifications Are 
not OK: No Consideration 
ALASKA PACKERS v. DOMENICO 
Ps contracted as seamen for D, but mid-performance, demanded more pay, 
threatening to breach, saying equipment was not as promised. 
Ps had pre-existing duty to work on ship and new K was not supported 
by fresh consideration. 
Employee Handbooks. 
Some courts have held that modifications to employee handbooks, decreasing 
employee rights, are unenforceable if not supported by fresh consideration.
  - RINCK v. ASSOCIATION 
  OF RESERVE CITY BANKERS 
  Court held that Ds promise to keep Ps job post-merger was not enforceable 
  b/c it wasn’t supported by consideration.
 
  
Where Modifications are 
OK 
Unforeseen or Unanticipated 
Circumstances. KING v. DULUTH 
When party refuses to complete 
his K b/c of some unforeseen and substantial difficulties in performance, 
not known or anticipated by parties at outset, and opposite party promises 
to pay extra for completion, that promise to pay is supported by valid 
consideration. 
Justifiable Reliance/Mutual 
Rescission: Modifications may be enforced if modification induced 
justifiable material change in position or reliance and injustice will 
result if not enforced.
SCHWARTZREICH v. BAUMAN-BASCH 
P was hired as coat designer at fixed wage for fixed time period, but 
renegotiated for more money after being offered position at another 
place. Later, P was let go and sued for increased wage. 
Modification was result of mutual rescission, followed by new and valid 
K.
  - R2 holds that such 
  rationale is fictitious when rescission and new K occur simultaneously, 
  but court also could have said that it was enforceable b/c of change 
  in circumstances, learning of Ps real worth, and justifiable reliance 
  on new wage.
 
  
UCC Approach: 
modifications are enforceable w/o consideration, w/ several exceptions 
UCC 
§ 1-103, Supplementary General Principles of Law Applicable
Common law valid if not displaced 
by UCC 
UCC 
§ 2-209, Modification, Rescission, and Waiver: No new consideration 
necessary
Reasoning: K modifications, 
one sided or not, are an everyday affair. 
Exceptions 
Economic Duress. 
KELSEY-HAYES v. GALTACO P sold K metal tire parts. Formed 
K with set price in 1987, 1989 decided to discontinue manufacturing 
that part. Agreed to keep manufacturing them for several months in exchange 
for 30% price increase. Month later raised requirement to another 30%. 
At some point, P stopped paying for castings, amt equivalent to price 
increases. Modification was under duress.
  - Later K supercedes 
  earlier K unless there is duress.
 
  
        - Duress: manifestation 
        of assent is induced by an improper threat by another party that leaves 
        victim no reasonable alternative.
 
        - K-H had no choice 
        but to accept modification.
 
        
          - Couldn’t sue b/c 
          G would have stopped supplying.
 
 
Bad Faith: 
Party may only seek modification in good faith when there are unforeseen 
economic exigencies. Even here, it is bad faith to coerce one by wrongfully 
threatening breach. (Wrongful if there is a good defense of K) 
Statute of Frauds: Reliance 
that modification will be put in writing. 
BROOKSIDE FARMS v. MAMA 
RIZZO’S, INC. (1995) (p. 695) 
P sells D basil. There are some oral price modifications, even tho 
both parties knew there was a no oral modifications clause in K—D 
asks P to remove stems from basil, price is increased. 
D said that they would change the written K, never did. P stopped payment 
at some point. K enforceable despite no oral modifications statute.
  - K falls within dispute 
  of statute of frauds, UCC § 2-201:
 
  
        - K for sale of goods 
        for price of $500 or more is not enforceable by way of action or defense 
        unless there is some writing sufficient to indivate that K has been 
        made and signed by party against whom enforcement is sought.
 
        
          - General rule: oral 
          modifications not enforceable
 
          
        - EXCEPTIONS to written 
        requirement:
 
        
          - When they do not 
          materially alter underlying obligations
 
          - Where one party 
          reasonably relies on oral promise of another to reduce oral agreement 
          to writing
 
          - Where payment has 
          been made and accepted (This is a TX law, though)
 
          
      - There was also a 
      No Waiver clause that says that failure to demand full performance doesn’t 
      give rise to waiver
 
      
        - However, even if 
        there is no waiver, K still falls within rules (and exceptions) of statute 
        of frauds