Abstract: A disposable beverage container lid that includes a top wall with a drinking opening formed therein, an annular sidewall downwardly depending from the periphery of the top wall for engaging with the rim of a beverage container, a regulator valve formed directly underneath the drinking opening, and wave-breaker and periphery inhibitor recesses formed in the top wall, to greatly minimize accidental splashing of the liquid from the cup. The regulator valve includes side and bottom walls with apertures formed therein, with the apertures including generally taper shaped portions terminating in irregularly shaped edges. The wave-breaker recess has a sidewall portion that reflects waves of liquid from the regulator valve, and a sloped sidewall portion that defines a channel with the annular sidewall in which the regulator valve is disposed. The inhibitor recesses extend down into the channel to prevent waves of liquid traveling therethrough.