A more thorough explanation:

A retaliatory eviction is when a landlord evicts a tenant because the tenant exercised their legal rights. For example, if a tenant complains to the health department about unsafe living conditions, and the landlord responds by evicting the tenant, that would be a retaliatory eviction.

Not all states recognize retaliatory eviction as a defense, but some do. In New York, for instance, landlords are prohibited from evicting tenants in retaliation for making a good faith complaint about health or safety violations, or for enforcing their rights under the lease or rental agreement.

Other states, like California, presume that an eviction is retaliatory if it occurs within a certain amount of time after the tenant complains to a government authority or sues the landlord. However, some states, such as Idaho, Indiana, Missouri, North Dakota, Oklahoma, and Wyoming, do not provide any statutory defense for retaliatory eviction.

Retaliatory eviction is illegal because it violates a tenant's legal rights. Tenants have the right to live in safe and habitable conditions, and to enforce their rights under the lease or rental agreement without fear of retaliation from their landlord.

A tenant in an apartment complex complains to the landlord about a leaky roof that has caused water damage to their belongings. The landlord ignores the complaint, and the tenant decides to withhold rent until the issue is resolved. In response, the landlord files for eviction, claiming that the tenant has not paid rent. This would be considered a retaliatory eviction because the tenant was exercising their legal right to live in a habitable dwelling and to withhold rent until the issue was resolved.