A more thorough explanation:

The cardinal-change doctrine is a principle in contract law that states if the government makes a significant and fundamental change to a contract that was not originally agreed upon, the other party (usually a contractor) is no longer obligated to continue working under the contract. This is because the government has essentially breached the contract.

For example, if a contractor agrees to build a bridge for the government for a certain price and timeline, but the government later decides to change the location of the bridge or the materials to be used, this would be considered a cardinal change. The contractor could then argue that they are no longer bound by the original contract and may seek to renegotiate the terms or terminate the contract altogether.

Another example could be if a company agrees to provide a certain service to the government, but the government later decides to significantly increase the scope of the project without adjusting the compensation or timeline. This would also be considered a cardinal change, and the company may be released from their obligation to continue working under the original contract.

These examples illustrate how the cardinal-change doctrine protects contractors from being unfairly burdened by significant changes to a contract that were not originally agreed upon. It ensures that both parties are held accountable for their obligations and that any changes to the contract are made in good faith and with mutual agreement.