Article is pending a remake to account for changes. Some of the information below is not accurate.
The latest New World patch introduced new endgame mechanics allowing players to increase their gear score to a newly raised cap of 625 (up from 600). While you still can't craft or drop any gear over 600 gear score, you can upgrade 600 gear score items past this limit with the freshly added [item_umbralshardt1].
This mechanic also allows Upgrading Items to Legendary with Umbral Shards.
Umbral Shards can be obtain from completing the new Mutated Expeditions, as well as through endgame crafting and Gypsum Casts. The amount of Umbral Shards needed to upgrade an items increases exponentially as you upgrade it toward 625, meaning it is extremely easy to upgrade items up to around 610 gear score, but very difficult to get all the way to 625.
Umbral Shards Required to Upgrade Item
|Current Gearscore||Shards to Upgrade|
As you can see, you need more shards to upgrade an item from 624 → 625 than to upgrade an item from 600 → 619. That's quite the scaling!
I mentioned before that Mutated Expeditions are by far the best way to obtain Umbral Shards. Mutations range from level 1 to level 10, with each level progressively scaling in difficulty. Rewards increase with mutation level. In addition, your group is graded bronze, silver, or gold based on performance. Higher grades are also a way to increase your [item_umbralshardt1] reward. Your grade is based on several factors such as dungeon clear time, enemies killed, and most importantly respawn/wipe count. Wiping will not only significantly reduce your score, but also cause you to spend more time in the dungeon reducing your score even more.
Umbral Shard Rewards
Lets take a look at how to get the shards.
The rewards scale in a similarly exponential manner as Umbral Shard costs on items. Only completing up to level 4 or 5 expeditions will make it nearly impossible to upgrade gear past around 620. Completing tier 9 and 10 expeditions give huge payouts that will let you instantly upgrade entire gear loadouts and let you max out your items at 625.
Once you have 600 expertise, Gypsum Casts stop giving expertise bumps and instead award Umbral Shards. They give Umbral Shards based on the expertise of the item you are opening, so you want to open casts that correspond with your highest expertise items.
|Expertise Level||Shards Reward|
The Umbral shard rewards at 620+ totally dwarf the rewards at 600-610. For this reason, you should only open casts for your highest expertise gear slots. If you don't gather a lot of gypsum every day, it might be a good idea to save the casts for when you have higher level expertise in one of your gear slots.
600 Gear Score Crafting
This method of obtaining Umbral Shards is practically irrelevant, but it does exist. Whenever you craft a 600 gear score item, you receive an expertise bump up until 600 expertise. Once you reach 600 expertise, it begins giving out [item_umbralshardt1] rewards based on that slot's expertise level. Considering how much it costs to craft any 600 gear score item, and the very low reward values associated with this method, you can pretty much ignore this as a source of shards.
|Expertise Level||Shards Reward|
Truly low reward values.
To summarize, the best way of upgrading your gear with Umbral Shards is, full stop, Mutated Expeditions. If you can complete the highest levels, the amount of Umbral Shards you receive will make upgrading your gear pretty easy, all things considered.
If you end up stuck on lower levels, you will end up soft-capped to whatever gear score corresponds with that level of rewards. For this reason, smart, effective play will absolutely trump brute force grindy play on easy content. Gypsum Casts serve as a decent bonus, but won't provide meaningful progress toward a full 625 set of gear. Because of this, and the newly buffed expedition rewards (on top of umbral shards,) expeditions will be more rewarding than ever! Craft those Creature Bane weapons and Creature Ward armor sets, because squeaking out every possible advantage for maximum exponential rewards is well worth it.