Not a rule that blocks every injured person from suing, and not a promise that an employer can never be held responsible. Instead, it is the rule that when a workplace injury is covered by workers' compensation, that system is usually the employee's only remedy against the employer for that injury. In exchange for no-fault benefits like medical care and wage loss payments, the worker generally gives up the right to file a regular personal injury lawsuit against the employer.

In practice, this doctrine matters because it shapes what kind of claim can be made after someone gets hurt on the job. A worker may be entitled to workers' compensation benefits without proving the employer was careless, but usually cannot seek damages such as pain and suffering from the employer in court. That tradeoff can feel limiting, but it also means benefits may start without a long fight over fault.

For an injury claim, the doctrine often narrows the case to questions like whether the injury happened in the course of employment, whether the employer had coverage, and whether a third party may also be liable. In Hawaii, this rule appears in Hawaii Revised Statutes § 386-5 (2024), often called the exclusiveness provision. It generally makes workers' comp the exclusive remedy against the employer, while still allowing possible claims against a negligent third party in some situations.