[Chance]

Event materials are actively used for rituals, forging items, and other projects. These can be obtained in various ways: attending events (whether a DM-ran personalized event) or a public one (including warfare/raids). Like most items in the game these can be passed between characters or stolen depending on the circumstances. You can also craft materials like you would a unique item; here is an archived example of that. 

Event Material
See the DM Guide if you aren't sure on how that process works.

Generally, a material is a non-gear item that can be used for projects. While something like chest armor or a sword might give stats, materials are not equipped.

These are typically graded. The grade is a subjective label rather than absolute as no two objects are the same, and the value of something will vary depending on how it is used. 

This is from Grade S to Grade E. 
The lowest grade being something that is still considered rare and valuable (such as gold, or a diamond ring) but can generally be obtained through more conventional means. The more magically potent and desirable a material source the higher the grade. Most resources acquired on events are Grade D or C.

Not all materials are always graded, as this is a fairly new, and mostly optional standard, but it's good to be aware of it.

Event Resource
A resource is a mechanically unique type of material. It can be used to create items with custom stat lines entirely in-game.

To set a resource up, a DM uses their 'Edit' command and then 'special_resource_slots'. They can then choose a slot that the resource may enchant. Any stats on the resource are transferred to the target item, and afterwards the artificer is prompted to edit the name, description, and assign a unique tag as they desire.

As mentioned, the stats of the event resource are transferred to the target item. This can be anything that's possible with items (including negative stats).

For example: 'Nevermelt Snowflake' is a resource with 2 ice power, and has the 'special_resource_slots' 'weapon' enabled. A T1 Artificer faces a non-unique weapon and left-clicks Nevermelt Snowflake. Now they can edit the name, description, and unique tag of the target item. It gains 2 ice power and the resource is expended.

Generally as a DM you will want to include this in the unique tag of the resource. Something like '(Event Title) (Weapon Resource)'

Bonus HTML Tip (DMs only!): When editing the item's 'unique' variable, you can space the two tags like event name]<br>[Grade: B for tidy formatting in-game.