I am currently practicing game design and development by implementing singular (or a small set) of mechanics in Unity. For example, -- and this is relevant towards the end -- I've just finished a small MOBA-style system that implemented a few mechanics: (1) Three lanes with respawning enemy and ally creeps/minions, (2) Towers at the ends of each lane that attack the player characters and minions, (3) A final "boss tower" whose defeat is the victory condition, and (4) Player characters are equipped with four spells from a set of implemented spells.

Point 4 is the relevant mechanic here: I implemented the set of spells as an XML document. The XML document lists the spells and their properties (e.g., type, mana cost, damage per second, etc.), allowing them to be retrieved and converted into a C# list at runtime. Player characters then select and equip spells from this C# list.

I'm wondering: Is a similar methodology used to implement thousands of unique items in RPGs and other loot-based games? If not, or even if so, what other methods are there for implementing the items in these games?

I am currently practicing game design and development by implementing singular (or a small set) of mechanics in Unity. 

For example, -- and this is relevant towards the end -- I've just finished a small MOBA-style system that implemented a few mechanics:

1. Three lanes with respawning enemy and ally creeps/minions,
2. Towers at the ends of each lane that attack the player characters and minions,
3. A final "boss tower" whose defeat is the victory condition, and
4. Player characters are equipped with four spells from a set of implemented spells.

Point 4 is the relevant mechanic here: I implemented the set of spells as an XML document. The XML document lists the spells and their properties (e.g., type, mana cost, damage per second, etc.), allowing them to be retrieved and converted into a C# list at runtime. Player characters then select and equip spells from this C# list.

I'm wondering: Is a similar methodology used to implement thousands of unique items in RPGs and other loot-based games? If not, or even if so, what other methods are there for implementing the items in these games?