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 South Dakota, the lease agreement is indeed a crucial document for both residential landlords and tenants as it outlines their rights and responsibilities. While oral agreements are legally binding, written leases are more common and provide clearer protection for both parties. Tenants should thoroughly read and understand the lease before signing. If a tenant wishes to negotiate changes to the lease terms, such as allowing pets when the lease prohibits them, the tenant should discuss this with the landlord. Any agreed-upon changes should be written into the lease and initialed by both parties to ensure that the modifications are legally enforceable. It's important to note that South Dakota's landlord-tenant laws, which can be found in the state's statutes, supplement the lease agreement by providing additional rights and responsibilities. These laws are designed to provide a legal framework for the rental relationship and must be adhered to even if they are not explicitly mentioned in the lease agreement.