From Outwar Wiki
Item rarity is what defines an item and its value. Some items are basic and dropped every few kills in Diamond City which would make them more of a commonplace item. Other items however can only be achieved via raiding and hard work which makes their rarity and value much higher on the worth ladder. Also item rarity determines gemming costs.
Item rarity is as follows:

Common
These items are the easiest items to find and can be found almost anywhere, mostly from Diamond City mobs. Common items usually never sell on the Treasury for a worthwhile price.
Green Gem: 5 Points Blue Gem: 6 Points Red Gem: 7 Points White Gem: 8 Points
|

Uncommon
Uncommon items are a tad bit harder to find than common items and can be found from the more elite Outwar Mobs. Also a few gods can be considered uncommon such as Warlord's belt of battle.
Green Gem: 10 Points Blue Gem: 12 Points Red Gem: 14 Points White Gem: 16 Points |

Rare
Rare items can be lower end gods or sets that can be gaining killing mobs in diamond city.
Green Gem: 15 Points Blue Gem: 30 Points Red Gem: 45 Points White Gem: 60 Points
| 
Elite
Elite items are the medium end gods that you might find off weaker crew raids(Gods).
Green Gem:20 Points Blue Gem:45 Points Red Gem:70 Points White Gem:95 Points |

Godly
Godly Items can be found from the stronger crew raid gods. These gods have considerable power, but are not the strongest of their kind.
Green Gem:25 Points Blue Gem:60 Points Red Gem:95 Points White Gem:130 Points |

Brutal
Brutal items have insanely strong stats, and are some of the strongest gods in the game. They are dropped from the Blackhand, Fangore, and Sandelman raids.
Green Gem: 30 Points Blue Gem: 70 Points Red Gem: 110 Points White Gem: 150 Points |

Kingly
Kingly gods are owned by the prestigious elite of Outwar. Not many are seen because of their rarity. These are the strongest out items, and are hard to obtain.
Green Gem: 35 Points Blue Gem: 80 Points Red Gem: 125 Points White Gem: 170 Points |

Gems and Augments
Augments are stones that can be inserted into your items to give them additional statistics. Available augment slots are listed along the bottom of each item's rollover. Statistics from augments display on your item's rollover in GREEN.
Gems are valuable purchasable upgrades from the Blacksmith that increase the overall statistics of your item. Each item has 4 gem slots. Gem slots are listed on the right side of the item rollover. |