All equipment and items require their creator to have a blueprint for that item. This ensures that high-level items cannot be made by just anyone; they must be made by professionals - players who hold the correct blueprints.
Blueprinting should be an industry. Creating copies of blueprints should be lucrative.
Each blueprint may be mastered by a player by a certain number of research points. Research points are directly proportional to time; there will be so many blueprints in the game, that it will be infeasible for a single person to learn them all. People must specialize, share, and work together.
Each item has a set of prerequisite items that must be researched in order to research the item. See the diagram below.
item: 000250: name: iron ore category: material label: - ore 000300: name: iron sword prereq: - 000250 category: weapon label: - sword - iron party: player: blueprints: - 000250 - 000300