Shards
Shards are gemlike artifacts that slot into your Relics, Armor, and Weapons. Shards replaced Skill Spheres system and item Passives (while some items with unique passives still drop but have only one shard slot). Shards give your hero or your defenses extra stats or abilities, all green shards can buff only defenses and can be placed only in Relics, while blue shards will buff your hero and can be placed in Weapon and Armor. Shards can be moved between pieces of gear and be upgraded straight from your inventory. A weapon or piece of armor allows to hold up to 2 Shards and can only equip Hero (blue) Shards and relics can hold up to 3 Defense (green) Shards. Blue shards give you hero new abilities or stats while they are placed in any item currently equipped by that hero, but green (defenses) shards strengthen only that tower, where relic containing them is equipped.
Shards drop from shard packs obtained from victory chest at the end of every map, you will get Campaign shard pack after completing any Campaign and Chaos map, those packs can drop shards associated with Campaign packs. After completing Trials on Chaos difficulty, you will get guaranteed Campaign shard pack and 0-2 Chaos shard packs corresponding to the difficulty you are playing, those packs can award you with shards from specific pool linked to that difficulty and all others from lower Chaos difficulties. That means shards linked to higher Chaos levels are harder to get because the pool of shards is getting bigger and bigger with each difficulty.
Based on the higher level shard packs being able to drop from the lower pools, when editing the shard list attempt to downgrade what difficulty level shards drop from. It is not necessary to indicate a Chaos 1 shard could also be dropped from C2 or C3, but if you get a shard from a campaign pack that is listed at C1 that is a noteworthy edit.
Weapons with Fixed Shards
The weapons in the list below drop with fixed Shards. These Shards are locked in one of the Shard slots and can't be removed. Some of them also can't be upgraded. Most of them are sold by Wayfarer for Soul of Night.