Once the Inquisition has been formed, Harritt the blacksmith of Haven will provide the Inquisitor with the ability to craft armor and armor upgrades as well as weapon and weapon upgrades. As the story progresses the Inquisition will then move to Skyhold; after settling in, an arcanist will be recruited to provide the Inquisitor with an additional upgrade. These new upgrades are called runes and can be added to weapons for increased damage. The Inquisitor will also gain an additional crafting slot for weapon and armor schematics. These new slots are called masterworks, they can significantly improve whatever they are affixed to. However helmets and upgrades will not incur the additional masterwork slot. Adding crafting materials to the masterwork slot in the crafting menu is completely optional but highly recommended as they provide a significant boost to the quality of the item created.
Schematics for equipment are arranged into one of four tiers:
Tier 1 is the lowest, least expensive, and most commonly available. They often have two slots, a primary and an additional, and low material costs. Several are available from merchants in Haven, the Hinterlands, and Val Royeaux, but they should be phased out after level 7 as the enemies scale in strength and durability.
Tier 2 schematics are not as commonplace, but some can be bought from the Val Royeaux Schematics Merchant early on with sufficient coin, or they can be found in zones available after relocating to Skyhold. They drop in fewer containers with slightly lower frequency compared to Tier 1 schematics, making them slightly more difficult to obtain by comparison. They have three slots, a primary and two additional, consume a moderate amount of materials and consequently have far superior returns on investment compared to the Tier 1 schematics. They are best suited for characters between levels 8-15.
Tier 3 schematics are exceptionally rare to find and expensive in a handful of stores in the far reaches of hostile wilderness zones, but with the right materials and Fade-touched additions they can outclass even late-game Unique equipment. They generally have four slots, a primary and three additional, the highest material cost and consequently the highest yields. They are ideal for levels 16+. Many are guaranteed in the Hissing Wastes tombs.
Tier 4 schematics, which are obtained solely through downloadable content, are superior to Tier 3 schematics but typically by a smaller margin than other tiers. They do not take higher amounts of materials in the additional slots (i.e, the bonuses will not be higher) but can have higher base damage or armor levels, as well as always having masterwork slots. Most are guaranteed to appear at fixed locations, either for purchase or as loot. There are no Tier 4 schematics for weapon upgrades (Hafts, Grips, Pommels, Staff blades) or armor upgrades (Arms and Legs).
Helmets, weapon upgrades and armor upgrades are notable exceptions. They only have two slots at all tiers, but the material costs increase to allow for higher returns on investment.
Some schematics have a Superior or Masterwork variant, indicated by a gold icon ringed in orange. They are aesthetically identical to the schematic of the same name, but have higher material requirements and provide higher stats.
In many cases, it is prudent to save rare, higher tier materials (e.g. Bloodstone, Silverite), as well as Masterwork materials, for the higher tier schematics, and thus seek them out as quickly as possible, as even a Tier 2 schematic with Tier 1 materials such as Iron or Serpentstone can outperform a Tier 1 schematic with Tier 3 or even Tier 4 materials.