When using attributes, the only modifier applied is the last item to be equipped. For example, if you have a helmet that gives +6 attack damage, and then equip boots that give +50% attack damage, then only the boots would apply its effect. This is goes for all attribute effects with all items- equipping armor and then holding an item with the same attribute will override the armor's attribute. (This includes offhand as well).

In addition, removing any item with the attribute will cancel out all of the effects from that attribute, even if overridden by another item (as described above). For example, equipping boots with +10 heath and then a helmet with +5 will give the user +5 health from the helmet, but removing the boots will give the user no additional health (even though the +5 health helmet is still equipped)

This effect makes it very difficult to customize items, since you can never have overlap or the effects cancel. This is especially annoying when trying to create weapons with custom damage that can be used with armor that increases damage. I would appreciate it if this could be fixed.