First come, first served.

Access to a limited good, service, or opportunity is given in the order people arrive or make their claim. Those who act earlier receive priority over those who wait.

The saying presents arrival order as a simple rule for allocating something scarce. It can announce a policy, justify a refusal after supplies run out, or urge someone not to delay.

Use it for queues, reservations, limited stock, appointments, or other situations where availability is allocated by order of arrival. It is often stated as a practical rule, but may sound blunt when people have unequal ability to arrive early or when need, safety, accessibility, or prior entitlement should take precedence.