Express Conditions

A party seeking to sue on a contract must either show compliance with an express condition, or that the other party was in bad faith with respect to the condition, thereby excusing its performance.

If a contract contains a condition that performance must be satisfactory to the purchaser, that satisfaction will be judged by an objective standard, unless the contract involves personal taste, in which case the performance must be subjectively satisfactory to the purchaser (limited only by the purchaser's obligation to exercise good faith).

Constructive Conditions of Exchange

Unless otherwise specified, each party must perform its obligations under the contract to be able to demand performance from the other side.  Such mutual conditions precedent are constructive conditions of exchange.

The doctrine of substantial performance provides that if a party substantially performs, he or she can recover on the contract even though full performance has not been tendered.  What constitutes "substantial performance" varies from case to case, but it means something like "almost fully performing."

Divisible Contracts; Installment Contracts

If a contract is divisible, then performance of one divisible portion permits the plaintiff to demand performance from the defendant for that divisible portion, even if the plaintiff is in breach with respect to another divisible portion.

The fact that a construction contract requires periodic payments does not make it a divisible contract.

Under the UCC, if a contract is determined to be an installment contract, the buyer can reject a nonconforming shipment only if it substantially impairs the value of the installment and cannot be cured.

Under a UCC installment contract, a breach with respect to one installment is a breach of the total contract only if the nonconformity substantially impairs the value of the entire contract.

Immaterial Breach and Substantial Performance

Under the common law, the plaintiff can sue for breach of contract if she has substantially performed the contract, even if there is an immaterial (nonwilful) breach.

Under the UCC, except for an installment contract, the seller must tender the correct number of conforming goods at the time specified in the contract or the buyer can reject the goods without liability.  However, the seller has a limited right to "cure" after a nonconforming tender.

Constructive Condition of Cooperation

A condition of cooperation is implied into every contract.  A party who wrongfully hinders the other party's performance breaches the contract.

Obligations of Good Faith and Fair Dealing

Each party to a contract has an implied duty to cooperate with the other party in achieving the objects of the contract.  Failure of the plaintiff to discharge that implied duty is a defense in a suit on the contract.

Suspension or Excuse of Conditions by Waiver, Election

Waiver occurs when a party affirmatively represents that it will not act on a known right.  If the other party relies on the waiver to its detriment, the waiver becomes irrevocable.