The property for damage increase has a cap of 100%. The only way to go above that is by stacking slayers on a weapon and talisman. The fight skill primer masteries also unlock the ability to go to 300% damage increase with stacks. This is a base damage increase used in Ultima Online in all of the fighting skills. Archery, Fencing, Mace Fighting, Swordsmanship, Throwing and Tactics all benefit from damage increase.