Jim Thorpe Landlord-Tenant Lawyer, Pennsylvania

A legal doctrine that requires landlords to offer and maintain livable premises for their tenants. If a landlord fails to provide habitable housing, tenants in most states may legally withhold rent or take other measures, including hiring someone to fix the problem or moving out. See constructive eviction.

A business guest, or someone who enters property held open to members of the public, such as a visitor to a museum. Property owners must protect invitees from dangers on the property. In an example of the perversion of legalese, social guests that you invite into your home are called 'licensees.'

The many types of information presented to a judge or jury designed to convince them of the truth or falsity of key facts. Evidence typically includes testimony of witnesses, documents, photographs, items of damaged property, government records, videos and laboratory reports. Rules that are as strict as they are quirky and technical govern what types of evidence can be properly admitted as part of a trial. For example, the hearsay rule purports to prevent secondhand testimony of the 'he said, she said' variety, but the existence of dozens of exceptions often means that hairsplitting lawyers can find a way to introduce such testimony into evidence. See also admissible evidence, inadmissible evidence.

A commercial real estate lease in which the tenant regularly pays not only for the space (as he does with a gross lease) but for a portion of the landlord's operating costs as well. When all three of the usual costs--taxes, maintenance and insurance--are passed on, the arrangement is known as a 'triple net lease.' Because these costs are variable and almost never decrease, a net lease favors the landlord. Accordingly, it may be possible for a tenant to bargain for a net lease with caps or ceilings, which limits the amount of rent the tenant must pay. For example, a net lease with caps may specify that an increase in taxes beyond a certain point (or any new taxes) will be paid by the landlord. The same kind of protection can be designed to cover increased insurance premiums and maintenance expenses.

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 rental agreement that provides for a one-month tenancy that is automatically renewed each month unless either tenant or landlord gives the other the proper amount of written notice (usually 30 days) to terminate the agreement. Some landlords prefer to use month-to-month tenancies because it gives them the right to raise the rent after giving proper notice. This type of rental also provides a landlord with an easy way to get rid of troublesome tenants, because in most states month-to-month tenancies can be terminated for any reason.

The legally prescribed time limit in which a lawsuit must be filed. Statutes of limitation differ depending on the type of legal claim, and often the state. For example, many states require that a personal injury lawsuit be filed within one year from the date of injury -- or in some instances, from the date when it should reasonably have been discovered -- but some allow two years. Similarly, claims based on a written contract must be filed in court within four years from the date the contract was broken in some states and five years in others. Statute of limitations rules apply to cases filed in all courts, including federal court.

The basis of a contract. Consideration is a benefit or right for which the parties to a contract must bargain; the contract is founded on an exchange of one form of consideration for another. Consideration may be a promise to perform a certain act -- for example, a promise to fix a leaky roof -- or a promise not to do something, such as build a second story on a house that will block the neighbor's view. Whatever its particulars, consideration must be something of value to the people who are making the contract.

A legally binding contract in which a person or business promises to treat specific information as a trade secret and not disclose it to others without proper authorization. Nondisclosure agreements are often used when a business discloses a trade secret to another person or business for such purposes as development, marketing, evaluation or securing financial backing. Although nondisclosure agreements are usually in the form of written contracts, they may also be implied if the context of a business relationship suggests that the parties intended to make an agreement. For example, a business that conducts patent searches for inventors is expected to keep information about the invention secret, even if no written agreement is signed, because the nature of the business is to deal in confidential information.