The most important source of information about the rights and responsibilities of residential landlords and tenants is the written lease agreement. Some landlords prefer oral agreements, but it is more common for them to require the tenant's signature on a written lease—and a written lease protects the tenant more than an oral agreement. Be sure to read the lease carefully before you sign it.

If a tenant wants to change part of the lease, the tenant should discuss it with the landlord. If the landlord agrees, the landlord and tenant should decide how they want to word the change and then write it into the agreement. Both the tenant and the landlord should then initial the change. For example, many standard leases prohibit pets, but the landlord may be willing to accept a pet if the tenant puts down extra money as security (a pet deposit) to protect against any damage the pet might do.

A state’s landlord-tenant laws may provide additional rights and responsibilities and further define the rights and responsibilities identified in the lease agreement. These laws vary from state to state and are usually located in a state’s statutes.

In Delaware, the landlord-tenant relationship is primarily governed by the Delaware Residential Landlord-Tenant Code, which outlines the rights and responsibilities of both parties. While oral lease agreements are legally recognized, written lease agreements are indeed the most important source of information about the rights and responsibilities of residential landlords and tenants. A written lease serves as a binding contract that clearly specifies the terms of the tenancy, including rent, duration, and rules regarding the use of the property. Tenants are encouraged to read and understand the lease before signing. If a tenant wishes to negotiate changes to the lease terms, such as allowing pets, these changes should be discussed with the landlord, agreed upon, and then added to the written lease with both parties initialing the modifications to ensure that they are legally enforceable. It's important to note that while the lease agreement can provide a detailed outline of the landlord-tenant relationship, state law may grant additional rights and responsibilities that are not explicitly mentioned in the lease. Therefore, tenants and landlords should be aware of the Delaware Residential Landlord-Tenant Code as it may supersede or complement the lease agreement.