A unilateral mistake occurs when only one party in a contract is mistaken about a fundamental fact related to the contract. This mistake typically involves a misunderstanding about a significant aspect of the agreement, which can sometimes affect the enforceability of the contract.
**Example of a Unilateral Mistake:**
Imagine a buyer and a seller are negotiating the sale of a vintage car. The seller mistakenly believes that the car is a rare model worth $50,000, while in reality, it is a common model worth only $10,000. The buyer, however, is aware of the true value of the car and does not correct the seller's mistake. They agree on a sale price of $45,000.
In this scenario, the seller is operating under a unilateral mistake because they are misinformed about the car's value. The mistake affects the fundamental terms of the contract—specifically, the value of the car.
**Legal Implications:**
In many jurisdictions, a unilateral mistake will not necessarily void the contract unless the mistaken party can prove certain conditions, such as:
- The mistake is about a fundamental aspect of the contract.
- The mistake was not due to negligence or lack of due diligence.
- The other party knew or should have known about the mistake and took unfair advantage of it.
If the seller can demonstrate these conditions, they might have a legal basis to seek rescission of the contract or adjustment of the terms.