"But it was my fault."

Labor Code § 3600(a)(3) requires only that the injury be "proximately caused by the employment, either with or without negligence."

Read that last clause. Negligence — yours or anyone's — is simply not part of the question.

Which means all of this is irrelevant

You made a mistake. You were rushing. You were tired. You lifted wrong. You did not follow the procedure. You were not wearing the equipment. You had done it that way for years. Nobody else got hurt doing it.

None of that defeats a claim. The system was designed that way deliberately: workers gave up the right to sue their employers, and in exchange fault stopped being the question.

The most common reason a valid claim never gets filed is a worker who has decided on their own that it was their fault and therefore not covered. That reasoning is wrong, and it is expensive.

The narrow exceptions

§ 3600(a) does contain a short list, and it is short:

Intoxication — but only where it caused the injury, and it is the employer's burden to prove. A positive test alone is not enough, and lawfully prescribed medication is not "unlawful use of a controlled substance." More.

Intentionally self-inflicted injury.

Willfully and deliberately causing one's own death.

Being the initial physical aggressor in an altercation — not the person who argued. More.

Injury from a felony for which you were convicted.

And voluntary off-duty recreational, social, or athletic activity — unless it was a reasonable expectancy of the employment. More.

One rule that does reduce benefits

Labor Code § 4551 reduces compensation by one-half where the injury is caused by the employee's own serious and willful misconduct — with statutory exceptions, including where the injury results in death or a permanent disability of 70% or more.

But the standard is demanding, and it is the mirror image of the standard applied to employers under § 4553: it requires conduct that is intentional and wrongful, or done with knowledge that serious injury is a probable result and deliberate disregard of that knowledge.

Ordinary carelessness, a mistake, violating a rule, or working too fast does not meet it. Expect it to be raised anyway.

And the reverse is worth knowing

If your employer knew about a danger and did nothing, § 4553 increases your compensation by one-half — and Insurance Code § 11661 forbids insuring against it, so the employer pays it personally. Twelve-month deadline. How.