What legal remedies are available to a tenant whose landlord fails to maintain safe and livable rental space?
Depending on where you live a tenant may be able to withhold rent, pay for repairs herself and deduct the cost of the repairs from her rent (known as repair-and-deduct), sue the landlord, or break her lease and move out without liability for future rent. State laws usually specify the conditions under which tenants may take advantage of legal remedies such as rent withholding, however. For example, the repair problem must be major (not something minor like a leaky faucet), and the tenant must follow rules (that vary by state) such as the minimum amount of notice the tenant must provide the landlord before withholding rent or pursuing another option.
See the Nolo article Tenant Options if Your Landlord Won’t Make Major Repairs for more on the subject, and check out Nolo's 50-state charts of landlord-tenant law, such as tenant rights to withhold rent by state.