There are many defense items in the game but they are all very similar - defensive items are used to redeuce the amount of damage received from mobs. (You will find that this page is very similar to the page on Weapons ... and that should not be a surprise.)
As a single Player, we each have two "characters". Each of them has a number of "slots". There are many defensive item slots, compared to the single weapon slot. There are XXX main categories of defensive items:
- Belt or Sash
The defensive items all have very creative names, but these are not important. And really, all of the defensive items have exactly the same function. There is nothing different between gloves and shoes - they are just items with a different name and picture.
What is important is the Base Defense level on each item. Where weapons have a range of hit points, defensive items block a specific number of hit points from reaching your player/characters. When more hit points come in than all of the defensive items can absorb, the player loses points in the Health meter.
Like weapons, defensive items are limited by their level. A level 13 item might have a base damage level of 48, while a level 22 item might have a base damage level of 92. The higher the level, the more damage the item will absorb. This is one reason why we want to get to higher levels. We can't use a level 23 item until our player/characters reach level 23.
Another factor that affects defensive item effectiveness is the tier. Poor items absorb less damage than Common items. Rare items protect us less than Legendary, etc. This is not always the case, it's a generalization. For example, a Rare item might also have bonus Character Attributes, like Defense, Dexterity, and Luck. Because there are bonuses, it might have a lower base damage number. We get a little more here, and a little less there. Epic and Legendary items have a lot of attribute bonuses. Their base damage level is usually very high, but not always if there are good attribute bonuses.
Ideally we want defensive items that also have high Defense attribute values. For example, a suit of armor might have a base defense level of 90, plus a Defense attribute of +18. That's a total of 108 defense points for that one item.
When calculating damage against a mob, each weapon has its own damage value. The damage value of a spell/ability is not combined with the damage of a sword. But for defensive items, all defense values are totalled. There is no concept of a wound to the head or a stab in the torso. So we should think of all of the Character Attributes of all defensive items as cumulative - adding up to a final value of protection. We can see this at the bottom of the player/character screen, where there are total values for Dexterity, Defense, and all other attributes.
Rings and necklaces can be thought of as defense items too. While not active defense tools, they are "energized" with Character Attributes like Dexterity, Defense, Vitality, and Luck, to help increase the total amount of protection.
Dexterity can be considered a defensive attribute as well as offensive. Dexterity increases the chance of dodging an enemy attack. If they don't hit you because you dodged, then you effectively had a very high defense.
Vitality can be considered defensive. This attribute determines the total health value. Of course with a higher health value, more damage from a mob has less of a chance of killing a character.
While it's always nice to get the highest possible base damage value, some defensive items with a lower base value are preferable because of their bonuses. Experiment and decide what you prefer - a higher "specific" Defense value, or more bonuses. You might decide to hold on to a lower level defensive item with a lower base damage level simply because of the bonuses.