Weapon Enhancement system.
This is a system that can modify the base weapons of 5th edition, players can use it to improve weapons and gear but is also a way to justify and explain magic items existing.
Two parts make up this system, first is the making of the weapon process, then is any enhancements.
A note: Any weapon with three slots or more used will require attunement to benefit from the enhancements.
When you forge a weapon you choose a metal type, and you may also spend time and effort to forge in a sharpness. if you do so it does not cost you a slot to use but still costs 75% the amount to forge it in.
+1 = 375g
+2 = 750g
+3 = 1500g
These are the common buffs to add to a weapon. For spells* you can only cast certain spells and the usage of permency dust is needed, the permency table is a good base line but talk to the DM about what is and isnt allowed.
Elemental damage is: Fire, Cold, Acid, Thunder, Lightning, Posien
Divine damage is: Necrotic, Radient Psychic