http://breezewiki.vernccvbvyi5qhfzyqengccj7lkove6bjot2xhh5kajhwvidqafczrad.onion/minecraft/wiki/Difficulty
The regional difficulty value is clamped as follows: if (RegionalDifficulty < 2.0) value = 0.0;
else if (RegionalDifficulty > 4.0) value = 1.0;
else value = (RegionalDifficulty − 2.0) / 2.0; Thus, on Easy, where regional difficulty is never higher than 1.5, the clamped value is always zero.