California Legal Malpractice: Elements, Duties, and Defenses
The Core Framework
California legal malpractice is a professional negligence tort. A plaintiff must prove four elements: (1) the existence of an attorney-client relationship or a duty flowing from an intended-beneficiary or reliance theory; (2) a breach of the standard of care; (3) causation; and (4) actual loss. Causation has two prongs that questions love to separate: actual cause (the attorney's conduct was a substantial factor) and proximate or legal cause. In a litigation matter this is almost always proved through the case-within-a-case doctrine: the plaintiff must show that, but for the negligence, the underlying action would have been won or settled more favorably, and that the resulting judgment was collectible.
Duty and Scope
Duty arises from the retainer agreement, but the scope of the engagement governs. An attorney is generally not liable for failing to advise on matters outside the scope of representation unless the client reasonably believed the attorney undertook them. California recognizes limited duties to intended beneficiaries of an estate plan where the attorney's negligence defeats the testator's intent, and to non-clients in narrow circumstances, but courts are reluctant to expand liability broadly. A key trap is assuming an attorney owes a duty to an adverse party or to a third party who merely relied on the attorney's work.
Standard of Care and Expert Testimony
Breach is measured by what a reasonably competent attorney would do under similar circumstances, not by perfection or hindsight. Expert testimony is ordinarily required to establish the standard of care and breach unless the negligence is so obvious that a layperson could recognize it (for example, missing a statute of limitations deadline). Questions often test whether expert testimony is needed, and the answer usually depends on whether the alleged error requires specialized knowledge.
Defenses and Damages
The statute of limitations is one year from the plaintiff's actual or constructive discovery of the negligence, with an outer four-year limit from the date of the wrongful act. Other defenses include comparative fault, the judgmental immunity doctrine (an attorney is not liable for a good-faith exercise of professional judgment), lack of causation, and the collectibility requirement in litigation malpractice. Damages are limited to actual loss, not the speculative value of a lost opportunity that was never recoverable.
Rule of Thumb
When you see a malpractice fact pattern, identify the underlying case's outcome first. If the plaintiff cannot show the underlying claim would have succeeded and been collectible, causation fails regardless of how careless the attorney was.