contract disputes
To prove a breach of contract – that the other party did not do what is required by the contract – you must show:
A contract exists;
You did everything you were supposed to do under the contract, or there is a legally recognized reason that excuses you from not doing everything you were supposed to do;
The other party did not do everything that party was supposed to do under the contract;
You suffered damages, or did not get what you were supposed to get, as a result of the breach of contract. For example, you lost money because the other party did not do what was required by the contract.
To prove the existence of a contract, you must first be able to show that you and the other party formed a legally binding contract – see the article on Contract Formation. Assuming you can show there was a valid contract, you must prove what the other party did wrong or did not do under the contract. To do this, you must also show that what the other party did wrong, or did not do, was a “material” term ― that is, not a trivial or unimportant part of the contract. This means that what the other party did wrong, or did not do, was so important that you would not have entered into the contract if you had known about it ahead of time.
There are several different ways to calculate damages in a breach of contract action. Calculating damages means you must show how much money you lost by the other party’s failure to do what was required under the contract. Usually, the amount of your damages is what you would have gotten if everyone had done what they were supposed to do under the contract.
There are two types of damages ― “direct” damages and “consequential” damages. Direct damages are the direct result of the other party not doing what was required under the contract. For example, you are a restaurant owner and pay a contractor, in advance, $15,000 to build a fence and other improvements to a back patio, which are necessary for you to be able to serve customers there. But the contractor never does the work. Your direct damages are $15,000.
In contrast, consequential damages are not always caused by the other party failing to do what was required under the contract, but were caused by the other party’s failure in your particular case. In order to get consequential damages, however, you must be able to show that you and the other party were both aware, when you entered into the contract, that the specific type of damages you are seeking to recover might occur if one of the parties did not do what they were supposed to do so.
In the example above, you might be able to show that both you and the contractor were aware, when you entered into the contract, that, if the contractor never did the work on the patio, you would not be able to serve as many customers and therefore you would lose profits as “consequence” of the contractor’s failing to do the work. However, you would also need to prove that you were in fact unable to serve as many customers as you would have done if the contractor had done the work, and how much money you actually lost as a result.
Another way of saying this is that you cannot recover damages that are “speculative,” indefinite, or imaginary. Your damages must be reasonably certain and directly traceable to the other party’s breach of the contract. For example, if you paid someone to build a racing car for you, and they never built it, you would be able to claim “direct” damages in the amount of money you paid the person who did not do what they were supposed to do. However, if, when you entered into the contract, you had never raced a car before and never even entered a car race, you would probably be unable to get as “consequential” damages money that you said you would have gotten for winning a prize for a car race.
合同纠纷：
为了证明违约行为——即对方未履行合同所要求的义务——您必须证明：
合同存在；
您已履行合同项下您应承担的全部义务，或有法律认可的理由使您未能完全履行义务可被豁免；
对方未履行其在合同项下应承担的全部义务；
由于违约，您遭受了损失，或未获得合同应给予您的利益。
例如：由于对方未按合同规定履行义务，导致您蒙受金钱损失。
为证明合同的存在，您必须首先证明您与对方已形成一个具有法律约束力的合同——参见《合同成立》相关内容。若能证明合同有效存在，您还必须证明对方违反或未履行合同义务。为此，您还需证明对方违背或未履行的是合同中的实质性条款（material term）——即该条款并非琐碎或无关紧要，而是重要到如果您事先知道对方不会履行，您就不会签订该合同。
损害赔偿的计算方式
在违约诉讼中，损害赔偿的计算方式有多种。损害赔偿是指您因为对方未按合同要求履行所遭受的金钱损失。一般而言，赔偿金额应使您处于如果双方均完全履约时本应获得的状态。
损害赔偿分为两类：
✔ 直接损害（Direct Damages）
✔ 间接损害 / 后果性损害（Consequential Damages）
直接损害
直接损害是指对方未履约所造成的直接结果。
例如：
您是一名餐厅老板，预先支付承包商 15,000 美元，用于在后院建造围栏和其它设施，以便您能在该区域为顾客提供就餐服务，但承包商从未施工。那么您的直接损害为：15,000 美元。
间接损害 / 后果性损害
间接损害并非对方违约必然会造成的损害，而是在您的特定情形下由对方违约造成的损害。
要获得间接损害赔偿，您必须证明：
在订立合同时，双方均意识到，如果一方不履行合同义务，该类损害有可能发生。
继续使用上述例子：
如果您能证明双方均在合同订立时意识到：若承包商未施工，您将无法接待更多顾客，因此会损失利润→ 这些利润损失就属于后果性损害。
但您还需证明：
您的确因此减少了接待顾客数量
您实际损失的利润金额
换句话说：
您不能请求推测性、模糊不清或凭空想象的损害赔偿。您的损害必须可以合理确定并且与对方违约行为之间具有直接因果关系。
例如：
您付钱请人制作一辆赛车，但对方从未制作。
您可请求的直接损害即您支付的费用。
然而，如果您此前从未参加过赛车比赛，也没有任何赛车经验，
那么声称因错失赛车比赛奖金而遭受损失，通常不能作为后果性损害获得赔偿。