The trial court erred in denying class certification in this action arising from allegedly terrible conditions at an apartment complex which the defendant owner had advertised as a luxury apartment building with many fancy amenities, but which was instead plagued with trashed common areas and other defects. Reliance is not an element of the claim for false advertising under B&P Code 17500, so the trial court erred in denying certification of that claim on the ground that individual questions of reliance undermined predominance. The breach of the implied warranty of habitability claim dealt solely with trash and other disagreeable things in the common areas of the apartment building, so the trial court should not have denied certification on the ground that individual questions predominated as to defective conditions in individual apartments. Nearly all the declarations on class certification attested to the trash in the common areas. Differences in measuring damages should not preclude class certification. For similar reasons, the class should have been certified on the nuisance claim. This case is unlike City of San Jose v. Superior Court (1974) 12 Cal.3d 447. There nuisance claims were brought on behalf of owners of many different properties in the neighborhood of the San Jose Airport. Here, just one property’s condition was at issue, so the case did not raise the same multitude of individual issues. A class should also have been certified on the claim for unreasonbly withholding security deposits on move-out. Proof of reasonable conduct by the defendant did not have to be made individual by individual. The trial court could control the manner of proof to preclude repetitive evidence and require summaries or other means of streamlining proof.