Here are some things that a landlord cannot do in California:

• Discriminate against tenants based on factors like race, religion, or disability.
• Retaliate against tenants for exercising their legal rights.
• Enter rental units without proper notice.
• Withhold necessary repairs.
• Increase rent excessively.
• Charge tenants the cost of offering a reasonable accommodation.
• Refuse to allow tenants with disabilities to make reasonable modifications to the rental unit.
• Raise rent to retaliate or as a form of punishment.
• Evict tenants for making a complaint against the landlord or for reporting code violations.
• Evict tenants without proper legal grounds.

Its important for landlords to understand and follow these rules to avoid legal violations and maintain strong relationships with their tenants. Tenants are empowered to assert their rights, ensuring their living conditions are safe and habitable.