From Dark and Darker Wiki
unique weapon drop % = 1.6% x3 (loot table rolls 3 times) = 4.8% drop chance (w/o luck)
50 luck = x1.64 * 4.8% = 7.872% 100 luck = x2.21 * 4.8% = 10.608% 250 luck = x3.54 * 4.8% = 16.992% 300 luck = 3.84 * 4.8% = 18.432%
From Dark and Darker Wiki
unique weapon drop % = 1.6% x3 (loot table rolls 3 times) = 4.8% drop chance (w/o luck)
50 luck = x1.64 * 4.8% = 7.872% 100 luck = x2.21 * 4.8% = 10.608% 250 luck = x3.54 * 4.8% = 16.992% 300 luck = 3.84 * 4.8% = 18.432%