Whitney Real Estate Lawyer, Pennsylvania

A promise that pledges nothing, because it is vague or because the promisor can choose whether or not to honor it. Such promises are not legally binding. For example, if you get a new job and promise to work for three years, unless you resign sooner, you haven't made a valid contract and can resign or be fired at any time.

A service contract that covers a major housing system--for example, plumbing or electrical wiring--for a set period of time from the date a house is sold. The warranty guarantees repairs to the covered system and is renewable.

A commercial real estate lease in which the tenant pays a fixed amount of rent per month or year, regardless of the landlord's operating costs, such as maintenance, taxes and insurance. A gross lease closely resembles the typical residential lease. The tenant may agree to a 'gross lease with stops,' meaning that the tenant will pitch in if the landlord's operating costs rise above a certain level. In real estate lingo, the point when the tenant starts to contribute is called the 'stop level,' because that's where the landlord's share of the costs stops.

A doctrine that prevents a defendant from re-litigating an issue after it has been lost. For example, if your neighbor sues you for putting up a fence on his land and the court rules that your fence extends beyond your property line, you can't later file your own lawsuit seeking a declaration that the property line is incorrectly drawn.

A legal principle or rule created by one or more decisions of a state or federal appellate court. These rules provide a point of reference or authority for judges deciding similar issues in later cases. Lower courts must apply these rules when faced with similar legal issues. For example, if the Montana Supreme Court decides that a certain type of employment contract overly restricts the right of the employee to quit and get another job, all other Montana courts must apply this same rule.

A remedy provided by a court that orders the losing side to perform its part of a contract rather than, or possibly in addition to, paying money damages to the winner.